Puzzle 1 You Who? "U2" has a concert that starts in 17 minutes and they must all cross a bridge to get there. All four men begin on the same side of the bridge. You must help them across to the other side. It is night. There is one flashlight. A maximum of two people can cross at one time. Any party who crosses, either 1 or 2 people, must have the flashlight with them. The flashlight must be walked back and forth, it cannot be thrown, etc. Each band member walks at a different speed. A pair must walk together at the rate of the slower man's pace: *Bono: - 1 minute to cross *Edge: - 2 minutes to cross *Adam:- 5 minutes to cross *Larry: - 10 minutes to cross For example: If Bono and Larry walk across first, 10 minutes have elapsed when they get to the other side of the bridge. If Larry then returns with the flashlight, a total of 20 minutes have passed and you have failed the mission. ==================================================================== Puzzle 2 Job Interview Three people are interviewing for the same job. The manager cannot decide which of the equally qualified applicants should get the job, so he devises the following: Each applicant is seated around a table facing each other, and has a large dot stuck onto their forehead. The manager places a spot on each of the applicants foreheads, and states to the applicants that each spot is either black or white. She then states that if an applicant sees a black spot, then they should raise their hand, and when they can tell her what color their spot is, the should do so immediatly and state why they are 100% sure of their color. All applicant raise their hand, and shortly there after one of the applicants goes to the manager with their answer. How was the applicant sure of the color of the dot? ==================================================================== Puzzle 3 Lost (an easy classic) You are lost in a forest. The forest is between two villages. In village A live only liars, they always lie. In village B people always tell the truth. You want to go to village B. Then you see a man from village A or B. You can ask him only one question. Which question will you ask him to know for sure where village B is ? ==================================================================== Puzzle 4 Marble puzzle (another easy classic) You have fifty bags, each with approximately one hundred balls inside. You have a weighing machine with a digital readout, with 3 places of decimals on the display, calibrated in grams, it is capable of weighing an infinite amount (but it won't have to). All of the balls in all of the bags weigh 1 gram, except in one bag in which all of the balls weigh 1.001 grams. You cannot tell by look or feel which bag has the heavier balls. How do you determine which bag contains the heavier balls? You can use the weighing machine only once (which means you can obtain only one reading from it before it self destructs). ==================================================================== Puzzle 5 Good bargain Two strangers from different parts of America both build simular apartment buildings in their home towns. By chance, they both forget an important part of thier project. They each, once again by chance, call the same national hardware store and order the missing items. The prices they are quoted are as follows: one will cost them $2. two will cost them $2. twelve will cost them $4. and a hundred and fourty-four will cost $6. What was the item they needed? ==================================================================== Puzzle 6 Grain silos Three grain silos have the following capacity: A 8000 kilos B 5000 kilos C 3000 kilos A is full, B and C are empty. Can you, without weighing, put 4000 kilos in silo A and 4000 kilos in silo B? ==================================================================== Puzzle 7 Big Ben A clock strikes '6' in 5 seconds. How long does it take to strike '12'? ==================================================================== Puzzle 8 Make a Deal Chris is a contestant in a game show called Monty's Revenge. In Monty's Revenge, there are three closed doors in front of Chris. Behind one of the doors is a fabulous prize (say tons of Kamei puzzles), behind the other two doors is something nasty (say Clem's hockey equipment). Chris is asked to pick a door - which he does. Now, the host of the show, Monty, makes the following offer to Chris: "Wait, wait, wait... Before you open that door and take what's behind it, let me make this a little more interesting. I know exactly where the fabulous prize is, so what I'm going to do is open one of the two doors that you didn't pick, where I know the prize isn't." Monty opens one of the other two doors, and true to his promise, there lies some of Clem's hockey equipment. Monty resumes his offer, "So, now we have two closed doors - the door you chose, and this other one here. Would you like to keep whatever's behind the door you chose - or would you like to change to this other closed door first?" What should Chris do? Should he keep his door, or should he switch? Why? ==================================================================== Problem 9 The Long and the Short of it What five-letter word becomes shorter when you add two letters to it? ==================================================================== Problem 10 Check Please Three people check into a hotel. They pay $30 to the manager and go to their room. The manager finds out that the room rate is $25 and gives $5 to the bellboy to return. On the way to the room the bellboy reasons that $5 would be difficult to share among three people so he pockets $2 and gives $1 to each person. Now each person paid $10 and got back $1. So they paid $9 each, totalling $27. The bellboy has $2, totalling $29. Where is the remaining dollar? ==================================================================== Problem 11 Death in Spain Not far from Madrid, there is a large wooden barn. The barn is completely empty except for a dead man hanging from the middle of the central rafter. The rope around his neck is ten feet long and his feet are three feet off the ground. The nearest wall is 20 feet away from the man. It is not possible to climb up the walls or along the rafters. The man hanged himself. How did he do it? ==================================================================== Problem 12 That'll Show Them! A boy has just purchased a fishing pole it is 6.5 feet long. The boy has to take a bus home and when the bus comes he is about to get on when the Bus driver informs him of the rule that no object longer than 4 feet can be taken aboard the bus. The boy then goes back into the store and gets something. He then catches the next bus and is able to board it and get home. What did the boy get? He did not alter the pole in anyway it stays intact. ==================================================================== Problem 13 Can't Count Higher Than 2 There are two fathers and two sons on a boat. Each person caught one fish. None of the fish were thrown back. Three fish were caught. How is it possible? ==================================================================== Problem 14 Lights Out There is a 2 story house with 3 bedrooms on the second floor. There are 3 light switches on the first floor, each controlling the light in one bedroom. The lights are all currently off. Each switch controls exactly one room, but there is NO WAY to determine which room is controlled while you are still on the first floor (I guess there must be no windows into the rooms). You will have to go up the stairs to actually determine what happens when a switch is set. The challenge is to determine which switch controls which light while only traversing the stairs one time (i.e., you can set the switches in any state you want and then go up the stairs and make your announcement of which switch controls which light). How can this be done? ==================================================================== Problem 15 The Blind Can See There are three prisoners brought out by the warden and offered a chance for freedom. The first prisoner (A) has two eyes, the second prisoner (2) has one eye, and the third prisoner (III) has no eyes (blind). The warden sits the three prisoners in chairs facing each other. The warden informs the prisoners that he has a total of five hats; two red and three white. He then puts one hat on each prisoner's head. Each prisoner; therefore, has a chance to see the other two prisoners' hats, but not his own. If any of the prisoners can guess his own hat color, he may go free; but if he gives a wrong answer, he will be shot. If the prisoner can not be certain, he may pass, and stay in prison. The two-eyed prisoner looks at the other two hats, and is unable to give a confident answer. He passes. The one-eyed prisoner waits for the first prisoner to finish answering, then looks around, and passes because he can not be confident in his answer. Upon hearing this, the blind prisoner confidently states the color of his hat, and the warden releases him. What is the color of the blind prisoner's hat, and how did he know? ==================================================================== Problem 16 Oops Soldier A has a brother B who was wounded in a battlefield. This brother B, who is also a soldier, claims that he does not have any brother!!! How can this be? ==================================================================== Problem 17 You can just tell There are two types of human being. Liars and truth-tellers. Liars always lie, the other always tells the truth. There are 4 men: Andrew, Bob, Chris and Dave. Their statements are: Andrew: Bob is a liar Bob : Both Andrew and Chris always lie Chris : Dave is a liar Dave : Only Bob tells the truth Who lies and who tells the truth?? ==================================================================== Problem 18 Traffic Jam There are two jars of equal capacity. In the first jar there is one amoebae. In the second jar there are two amoebae. An amoebae can reproduce itself in three minutes. It takes the two amoebae in the second jar three hours to fill the jar to capacity. How long does it take the one amoebae in the first jar to fill that jar to capacity? ==================================================================== Problem 19 Say that 11 times fast Insert punctuation so that the following makes sense: John while James had had had had had had had had had had had a better effect on the teacher ==================================================================== Problem 20 Simple English Can you arrange these letters in order to make one word? NEW DOOR ==================================================================== Problem 21 Fruity or Dry? Three boxes are labeled "Apples", "Oranges", and "Apples and Oranges". Each lable is incorrect. You may select only one fruit from one box. (No feeling around or peeking permitted). How can you label each box correctly? ==================================================================== Problem 22 Dog's Mead A crossnumber puzzle: An old english puzzle, concerning a farm that has been inthe Dunk family for some years. A part of the farm is known as Dog's Mead. Additional information: The year is 1939 4840 square yards = 1 acre 4 roods = one acre 20 shillings = 1 pound ------------------------------------ |1 | |2 |3 | |XXXX|4 | | | | | | |XXXX| | | | | | | |XXXX| | ------------------------------------ | |XXXX|5 | |XXXX|6 | | | |XXXX| | |XXXX| | | | |XXXX| | |XXXX| | | ------------------------------------ | |XXXX| |XXXX|7 | | | | |XXXX| |XXXX| | | | | |XXXX| |XXXX| | | | ------------------------------------ |XXXX|8 | |9 | |XXXX|XXXX| |XXXX| | | | |XXXX|XXXX| |XXXX| | | | |XXXX|XXXX| ------------------------------------ |10 | |XXXX|11 | |12 |13 | | | |XXXX| | | | | | | |XXXX| | | | | ------------------------------------ | |XXXX|XXXX|XXXX|14 | | | | |XXXX|XXXX|XXXX| | | | | |XXXX|XXXX|XXXX| | | | ------------------------------------ |15 | |XXXX|16 | |XXXX| | | | |XXXX| | |XXXX| | | | |XXXX| | |XXXX| | ------------------------------------ Across 1. Area in square yards of Dog's Mead 5. Age of Martha, Father Dunk's Aunt 6. Difference in yards between length and bredth of Dog's Mead 7. Number of roods in Dog's Mead times 8 down 8. The year the Dunks acquired DOg's Mead 10. Father Dunk's age 11. Year of mary's birth 14. Perimeter in yards of Dog's Mead 15. Cube of Father Dunk's walking speed 16. 15 across minus 9 down Down 1. Value in shillings per rood or Dog's Mead 2. Square of the age of Father Dunk's mother-in-law 3. Age of Mary, Father Dunk's other daughter 4. Value in pounds of Dog's Mead 6. Age of Ted, Father Dunk's son, who is twice the age of his sister Mary in 1945 7. Square of the bredth of Dog's Mead 8. Time in minutes it takes Father Dunk to walk 1 1/3 times around Dog's Mead 9. The number which, multiplied by 10 across, gives 10 down 10. See 9 down 12. Addition of the digits of 10 down plus 1 13. Number of years Dog's Mead had been in the Dunk family ==================================================================== Problem 23 Faster, Faster A truck travels 15 mph for the first half of the distance of a trip. How fast must it travel in the second half of the distance in order to average 30 mph for the total trip? ==================================================================== Problem 24 Next in the List What do the following words have in common: deft, first, calmness, canopy, laughing, stupid, crabcake, hijack. ==================================================================== Problem 25 Standing in the Corner A standard chessboard is truncated by removing two corner squares diagonally opposite each other. Can thirty-one dominos, each able to cover two adjacent squares, be used to cover all sixty-two remaining squares of the truncated chessboard? If so, how? If not, why not? ==================================================================== Problem 26 Simple Spelling Supply a digit for each letter so that the multiplication equation is correct. There is only one set of digits that will work. A given letter always represents the same digit: A B C D E x 4 ----------- E D C B A ==================================================================== Problem 27 Daughter's Letter Home Supply a digit for each letter so that the addition equation is correct. There is only one set of digits that will work. A given letter always represents the same digit: S E N D + M O R E ---------- M O N E Y ==================================================================== Problem 28 Weighty Issues If you have a 2-pan balance scale, what is the minimum number of weights that can be used to weigh any number of pounds from 1 to 40, and what are those weights? ==================================================================== Problem 29 Sleeping it Off On on occasion King George II of England went to sleep on the night of September 2 and did not wake up until the morning of September 14. His doctors and advisors were not particularly worried by this. Maybe this was because they knew that a similar sort of thing had once happened to King Henry III of France. He had fallen asleep on December 9 and not wokon until December 20. We know that monarchs in those days had a pretty easy life, but what was going on here? ==================================================================== Problem 30 Wet Dreams You have 6 pails in a row, the first 3 full of water, the second 3 empty: |X| |X| |X| | | | | | | |X| |X| |X| | | | | | | --- --- --- --- --- --- 1 2 3 4 5 6 By moving only one pail, line them up so that full pails and empty ones alternate. ==================================================================== Problem 31 Saved by the Bell What are the next four numbers in this series: 12, 1, 1, 1, 2, 1, 3... ? ==================================================================== Problem 32 Counting on You How are the following numbers arranged? 0, 2, 3, 6, 7, 1, 9, 4, 5, 8 ==================================================================== Problem 33 Trees in the Forest Plant 10 trees in 5 rows of 4 trees each. ==================================================================== Problem 34 Woof! Nine wolves are in a square enclosure at the zoo. Build two more square enclosures and put each wolf in a pen by itself. ---------------- | W W W | | | | | | | | W W W | | | | | | | | W W W | ---------------- ==================================================================== Problem 35 One Level Harder Without lifting your pencil from the paper, join all 16 dots with 6 straight lines * * * * * * * * * * * * * * * * ==================================================================== Problem 36 You Would Think You Couldn't Do It This is an unusual month - Santa, snow and so on. This is an unusual paragraph, too. How quickly can you find out what is so uncommon about it? It looks so ordinary that you may think nothing is odd about it until you match it with most paragraphs this long. If you put your mind to it and study it you will find out, but nobody may assist you; do it without any coaching. Go to work and try your skill at figuring it out. Par on it is about half an hour. Good luck - and don't blow your cool. ==================================================================== Problem 37 Strict Terms Find the product of the following: (x+a)(x-b)(x+c)...(x-z) ==================================================================== Problem 38 A Bumpy Problem A Middle Eastern potentate died, leaving 17 camels. His will specified that they be divided among his three sones as follows: 1/2 to the oldest son 1/3 to the second son 1/9 to the youngest son The three sons were puzzling over how this could be done when a wise man happened to ride by on a camel. How did the wise man solve their problem? ==================================================================== Problem 39 Burning Bright You have in your possession two pieces of string. Let's say that each is a couple of feet long, but it doesn't really matter. And they can both be different lengths, it doesn't matter either. And they're burnable, like the fuses that they use to light dynamite. Now you could light either end of either string, and it would burn. In fact, if you lit one end of a string, it would burn in exactly an hour. But here's the wrinkle: the strings do not burn in a constant, at a constant rate. For example, the string might burn for two minutes and then go crazy and burn like mad and then slow down. You don't know what rate the string's burning at any specific time. All you know is that in an hour's time, the whole string is burned. The question very simply is, with the Zippo lighter and these two strings, how would you measure 15 minutes of time? ==================================================================== Problem 40 Joe Hoofs it Home Joe used to have his wife drive him to the train station and then he'd take the train and go to work. At the end of the day, he'd get on the train to come home. He'd get to the train station and his wife would meet him there and they'd drive home. Well one day, Joe decides to leave work early at 4 pm. Needless to say, he gets to the train station an hour early. Rather than call his wife, it's a nice day and he decides to hoof it. So he starts walking in the direction she'll be driving. And low and behold, he sees his wife coming up the road and she sees him by the side of the road. They get in the car and they drive home and arrive 20 minutes earlier then usual. Don't forget - she left home at the usual time. How long was he walking before they met? Notice, there's no mention of how long she was driving, how fast he walked, what train he took, and what any other the distances were. How long was he walking before she picked him up? ==================================================================== Problem 41 The Prisoner's dilemma Many years ago a prisoner was condemned to die. He was in his cell, and the warden came to visit him. He said to the prisoner that his odds of dying the next day are 100%. But the warden wants to increase the prisoner's chances to 50%. The warden gives the prisoner 2 shoeboxes, one with 50 white marbles, and one with 50 black marbles. The warden will come in blindfoldeed and pick a marble out of one of the boxes. White, he lives. Black, he dies. The marbles can be arranged in any way. All the marbles must be used in either box. Is there any way to improve his chances above 50%? ==================================================================== Problem 42 Armored Planes It was a dark and stormy night. The location is a secret airfield somewhere in England during WW 2. The RAF had summoned one of England's most noted mathematicians to help them solve a problem. They were having a problem, because they were attempting to bomb Germany, and the German anti-aircraft fire based on the ground was inflicting heavy losses on the Brits. And their planes were being shot down right and left and the RAF have to do something to diminish their losses. Now clearly they could put armor plating on the bottoms of the fuselages and the wings, but there were several problems that came along with this. One, they would have to become ground based planes, because they wouldn't be able to fly. The ones that could would have their range considerably reduced, and of course, their ability to carry cargo and bombs and fuel would be diminished because of this additional weight. So the mathematician crawls underneath the planes and looks at where the bullet holes are underneath them. Now there were bullet holes all over the place as you might expect. In the wings and the fuselage and seemingly distributed randomly on the undersides of these planes. He studies hundreds of planes, takes pictures, draws things and then he makes his recommendation. The question very simply is, what armor plating, if any, does he recommend putting on these planes, and why? ==================================================================== Problem 43 Boy, oh boy. Mr Smith has two children, at least one is a boy. Mr Jones has two children, the eldest is a boy. Is the probability that Mr Smith has 2 boys the same as Mr Jones's? ==================================================================== Problem 44 One Lump or Two? The beautiful young princess had a dilemma. She was in love with Igor, a blacksmith's son and a hunchback, but she wanted to marry him anyway. However, she knew that her father, the King, would not approve. Moreover if the King knew of their love, he would surely have the young man executed. They devise a plan to elope. Sadly, their plan is foiled and they are stopped at the castle gate by the guards who spotted Igor's hump. And they are brought before the King. Now, the King was indeed furious, but he decided show his court that he would offer Igor a sporting chance. He said he would take two pieces of paper and write the word, "Princess" on one piece and "Death" on the other, and the young lad could decide his own fate by selecting one of the slips of paper from a jar. If he picks "Princess", he gets the princess. "Death", he gets the death. However, he knows that the King is sneaky, and indeed the King writes "Death" on both pieces of paper. But despite this, despite this, Igor manages to win the princess' hand. How does he manage this? ==================================================================== Problem 45 A rose is a rose What do the following men have in common (besides all being dead)? Ulysses S. Grant, Rudyard Kipling, Woodrow Wilson, Grover Cleveland, and Calvin Coolidge ==================================================================== Problem 46 Eating Your Way to Knowledge A bookworm eats from the first page of an encyclopedia to the last page. The bookworm eats in a straight line. The encyclopedia consists of ten 1000-page volumes and is sitting on a bookshelf in the usual order. Not counting covers, title pages, etc., how many pages does the bookworm eat through? ==================================================================== Problem 47 Prime Cuts What is the least number of links you can cut in a chain of 21 links to be able to give someone all possible number of links up to 21? ==================================================================== Problem 48 Lock, Stock and Box You want to send a valuable object to a friend. You have a box which is more than large enough to contain the object. You have several locks with keys. The box has a locking ring which is more than large enough to have a lock attached. But your friend does not have the key to any lock that you have. How do you send it securely? Note that you cannot send a key in an unlocked box, since it might be copied. ==================================================================== Problem 49 In Rhyme A very bright and sunny Day The Priest did to the Verger say: "Last Monday met I strangers three None of which were known to Thee. I ask'd Them of Their Age combin'd which amounted twice to Thine! A Riddle now will I give Thee: Tell Me what Their Ages be!" So the Verger ask'd the Priest: "Give to Me a Clue at least!" "Keep Thy Mind and Ears awake, And see what Thou of this can make. Their Ages multiplied make plenty, Fifty and Ten Dozens Twenty." The Verger had a sleepless Night To try to get Their Ages right. "I almost found the Answer right. Please shed on it a little Light." "A little Clue I give to Thee, I'm older than all Strangers three." After but a little While The Verger answered with a Smile: "Inside my Head has rung a Bell. Now I know the answer well!" Now, the question is: How old is the PRIEST?? ==================================================================== Problem 50 Top Secret With his heart rate increasing steadily, James Bents (alias Lt-Colonel Ivanovic Zdanov, as far as the KGB were concerned) lined up behind the scientists who were walking towards the internal gate. Thanks to his forged documentation, he was able to pass through the two previous gates. He was aware that to get right inside the missile launch-pad, he would need to supply a password. He had been informed that the password changed daily. Only his extreme cool and many years of training enabled him to contain the fear. The two scientists in front of him reached the gate, which was patrolled by machine-gun wielding soldiers. He strained to hear the voices of the people ahead of him in the queue. "Twelve?" asked the guard. "Six," replied the first scientist. The first scientist strode through the gate as the second one walked to the guard. "Six?" asked the guard. "Three," replied the second scientist and walked through. Relief and confidience spread through Bents; the method that drove questions and answers was trivial. He stepped forward. "Nine?" asked the guard. Brents hesitated for a split second. This was an unpredicted complication, but his arduous conditioning allowed the secret agent to remain calm and as sharp as a razorblade. "Four and a half," he answered without blinking. Quite suddenly, the entire area was filled with floodlights. Alarm sirens broke the silence of the otherwise peaceful night. In a fraction of a second the Lt-Colonel realised his mistake. He tried to turn on his heels and run, but instantly felt the cold barrel of a machine-gun pressed against his neck. What was the secret agent's fatal mistake? ==================================================================== Problem 51 The Mountaineer An Austrian mountaineer leaved Zurglatt, his village, at eight o'clock in the morning, and started his climb towards the refuge Tirpitz, on Gross Glossen mountain. He walked at a steady pace, without stopping, and his increase in heart pulse rate was negligeable. He reached the refuge at three in the afternoon, ie seven hours since he left the village. At the refuge he rested, admired the view, scribbled some notes on his diary, sang three lieder's, ate two sausages and drank a litre of beer. He then slipped in his sleeping bag and fell asleep. The next morning, at eight o'clock, he started his descent, still with a steady pace, but faster, since he was travelling downhill. He reached Zurglatt at one in the afternoon, after walking for five hours. Could there be a point along the path where the mountaineer walked, on the outbound and the return journey, exactly at the same time of day? ==================================================================== Problem 52 The Desert Crossing You stand at the edge of a desert which is 1,000 miles wide at the shortest possible route. You have a cargo of 3,000 bananas. Your beast of burden is a camel who needs to eat 1 banana every mile he travels. He also can only carry a maximum of 1,000 bananas at a time. How many bananas can you deliver to the other side of the desert? a. you don't need water, b. you cannot carry anything, c. there are nothing else that you have access to in the desert. There is no trick -- everything is stated in the problem. ==================================================================== ==================================================================== Solutions: ==================================================================== ==================================================================== Puzzle 1 Solution 1: You Who? Bono and Edge cross first together - 2 minutes Bono crosses back with flashlight - 1 minute Adam and Larry cross with flashlight - 10 minutes Edge crosses back with flashlight - 2 minutes Bono and Edge cross together - 2 minutes Puzzle 1 Solution 2: Bono and Edge cross first together - 2 minutes Edge crosses back with flashlight - 2 minutes Adam and Larry cross with flashlight - 10 minutes Bono crosses back with flashlight - 1 minute Bono and Edge cross together - 2 minutes ==================================================================== Puzzle 2 Solution Job Interview Applicant 1 sees 2 black spots (on the other applicants foreheads). She thinks that if she had a white spot, then applicant 2 (and 3) would be seeing one white and one black, and would then instantly realize (since they are as bright as she is) "I see a white and a black. If I had a white spot, then the applicant with the black spot would be seeing two white spots, and would not have raised their hand. However, they DID raise their hand, therefore I must not have a white spot." Since neither of the other applicants instantly realized this, applicant 1 knows that she must have a black spot. ==================================================================== Puzzle 3 Solution Lost Ask the man which city he lives in. He will always point to village B. ==================================================================== Puzzle 4 Solution Marble puzzle Make a collection of marbles taking one from the first bag, two from the second bag, three from the third, and so on and so forth. Weigh the new collection and the weight in hundredths of a gram will tell what bag the heavier balls came from. ==================================================================== Puzzle 5 Solution Good bargain The people in the puzzle both forgot to add address numbers to their buildings. If each individual number cost them $2, then One (the number 1) will cost $2. . . and so forth. the number 0ne fourty four (1, 4, 4.) is three digits, and so costs 6 bucks. ==================================================================== Puzzle 6 Solution Grain silos A B C 8 0 0 Starting 5 0 3 Fill C from A 5 3 0 Move C to B 2 3 3 Fill C from A 2 5 1 Fill B from A (leaving 1 kilo in C) 7 0 1 Move all of B to A 7 1 0 Move C to B 4 1 3 Fill C from A 4 4 0 Move C to B ==================================================================== Puzzle 7 Solution Big Ben 11 seconds There is an interval of 1 second between each stroke. If the clock strikes 6, there are 5 intervals. If the clock strikes 12 there are 11 intervals. ==================================================================== Puzzle 8 Solution Make a Deal Always switch. Before you knew one of the doors, you chances of a win were 1 in 3. THOSE ODDS DON'T CHANGE because Monty told you a door. However, now if you re-select the unchosen door, your odds are 2 in 3. Essentially, what Monty is asking you, having shown one of the two doors you didn't select originally and offering you the other, is, "Do you want to switch from selecting door 1, or take doors 2 and 3". So by switching, you are making your original choice 2 doors instead of 1. ==================================================================== Puzzle 9 Solution The Long and the Short of it Chad... Watch out... the title I put on this one might give it away too easily "Short" ==================================================================== Puzzle 10 Solution Check Please Each person paid $9, totalling $27. The manager has $25 and the bellboy $2. The bellboy's $2 should be added to the manager's $25 or subtracted from the tenants' $27, not added to the tenants' $27. ==================================================================== Puzzle 11 Solution Death in Spain He stood on a 3 foot high piece of ice, and was stangled as it melted. Once it melted, there is no evidence of its existance. ==================================================================== Puzzle 12 Solution That'll Show Them! The boy gets a cubical box, 4 ft. x 4 ft. x 4 ft. Inside a box this size you can put a 6.5 foot fishing pole, with room to spare. ==================================================================== Puzzle 13 Solution Can't Count Higher Than 2 Fishing that day were a man, his father and his son, only 3 people. ==================================================================== Puzzle 14 Solution Lights Out Interesting variation to the light in the tower, solved the same way. Flip on switch one for 30 seconds. Flip it off and flip on switch two. Go upstairs and check the bulbs in the rooms. The one that is on is connected to switch two, the one that is off AND WARM is connected to switch one, and the one that is off and cold is connected to switch 3. Alternately, turn on two of the light switches and leave them on for a few minutes. Turn one switch off and then go upstairs. The light that is on is controlled by the on switch, the light that is warm is controlled by the switch that used to be on, and the remaining switch controls the remaining light. ==================================================================== Puzzle 15 Solution The Blind Can See Prisoner A must see at least one red hat, or she would know that her hat is red since they are not all white. Prisoner 2 also must see at least one red hat, and further, that hat had to be on Prisoner III, otherwise she would know that her hat was red (since she knows Prisoner A saw at least one red hat). So Prisoner III knows that her hat is red, without even seeing the others' hats. ==================================================================== Puzzle 16 Solution Oops Soldier A is a woman. ==================================================================== Puzzle 17 Solution You can just tell Chad, check this one carefully. I think it is correct, but have no answers to check against. Andrew: Bob is a liar T Bob : Both Andrew and Chris always lie L Chris : Dave is a liar T Dave : Only Bob tells the truth L Start with Dave. If he is a Truthteller, then the statement he makes False, because he also tells the truth. Therefore Dave MUST be a Liar. If he is a Liar, then more than one person is a Truthteller. If he is a Liar, then Chris is telling the truth, and is Truthteller. Bobs statement then is a falsehood, so he is a Liar, which makes Andrew a Truthteller as well, and his statement is a true one, and makes him a second Truthteller. ==================================================================== Puzzle 18 Solution Traffic Jam Three hours and three minutes. ==================================================================== Puzzle 19 Solution Say that 11 times fast John and Jim are in the same English class, and have written a similar sentence. However... John while James had had "had", had had "had had". "Had had" had had a better effect on the teacher ==================================================================== Puzzle 20 Solution Simple English Yes: ONE WORD ==================================================================== Puzzle 21 Solution Fruity or Dry? Select a fruit from the "Apples and Oranges" box. What ever it is, place the appropriate single fruit label on that box, move the other single fruit label from its current box (third box) to the one from which you removed the first label (second box), and place the "Apples and Oranges" label on the third box. ==================================================================== Puzzle 22 Solution Dog's Mead Consider 15A (across) first, look at repercussions with 11A, 16A and 7D. ------------------------------------ |1 | |2 |3 | |XXXX|4 | | | | | | |XXXX| | | 3 | 8 | 7 | 2 | 0 |XXXX| 5 | ------------------------------------ | |XXXX|5 | |XXXX|6 | | | |XXXX| | |XXXX| | | | 4 |XXXX| 9 | 1 |XXXX| 4 | 4 | ------------------------------------ | |XXXX| |XXXX|7 | | | | |XXXX| |XXXX| | | | | 0 |XXXX| 2 |XXXX| 3 | 8 | 4 | ------------------------------------ |XXXX|8 | |9 | |XXXX|XXXX| |XXXX| | | | |XXXX|XXXX| |XXXX| 1 | 1 | 1 | 0 |XXXX|XXXX| ------------------------------------ |10 | |XXXX|11 | |12 |13 | | | |XXXX| | | | | | 7 | 2 |XXXX| 1 | 9 | 1 | 8 | ------------------------------------ | |XXXX|XXXX|XXXX|14 | | | | |XXXX|XXXX|XXXX| | | | | 9 |XXXX|XXXX|XXXX| 7 | 9 | 2 | ------------------------------------ |15 | |XXXX|16 | |XXXX| | | | |XXXX| | |XXXX| | | 2 | 7 |XXXX| 1 | 6 |XXXX| 9 | ------------------------------------ ==================================================================== Puzzle 23 Solution Faster, Faster Can't be done. (Infinite speed would be necessary) ==================================================================== Puzzle 24 Solution Next in the List The all have 3 consecutive letters of the alphabet in them. ==================================================================== Puzzle 25 Solution Standing in the Corner No. Consider that each domino must, MUST, cover both a white square and a black square. By removing the 2 corners diagonally opposite each other on the chessboard, you are removing either 2 black or 2 white squares, leaving you with either 32 white and 30 black, or 30 black and 32 white squares, making it impossible to cover the entire board with dominos (the last one to be placed would either have to cover 2 black or 2 white squared, not possible). ==================================================================== Puzzle 26 Solution Simple Spelling 2 1 9 7 8 x 4 ----------- 8 7 9 1 2 Since A multiplied by 4 yields only a one-digit number, it must be either 1 or 2. Since E x 4 must yield an even number, A must be 2 Since the only numbers that, when multiplied by 4, yield a figure ending with 2, are 3 and 8, E must be either 3 or 8 Since A x 4 cannot be 13 - i.e., cannot be a two-digit number, it must be 8. Therefore E is 8 Since a 3 is carried over to D in the top line, it must also be added to D in the answer. We can see that B x 4 must yield a one-digit number. That means that B must be either a 1 or a 2. If it is a 2, then with the 3 added to it, D would be 11 - impossible. So be must be 1 Now consider D. The question here is simple: What number, when multiplied by 4 and enlarged by the carried 3, will yield a number ending in 1? Two numbers fill the bill: 2 and 7. Since we already know that B is 2, the missing number must be 7 The B in the top line must have a carried 3 added to it in order to yield 7 in the answer, so C, when its carried 3 is added to it, must be at least 30. The only numbers that will work, therefore, are 7, 8 or 9. a little experimentation shows that 9 is the missing number ==================================================================== Puzzle 27 Solution Daughter's Letter Home 9 5 6 7 + 1 0 8 5 ---------- 1 0 6 5 2 ==================================================================== Puzzle 28 Solution Weighty Issues 4 of them: 1, 3, 9 and 27 ==================================================================== Puzzle 29 Solution Sleeping it Off The kings each slept one night only. The calendar changed in France in 1582 and in England in 1752 from the Julian to the Gregorian calendar in order to correct for the cumulative error of lack of leap years. Pope Gregory XIII ordered 10 days to be dropped in 1582, an order which was followed by Catholic countries such as France, but not by Protestant ones such as England. England eventually adopted the improved calendar in 1752, by which time an additional day had to be adjusted for. By thge way, the American colonies were also under the English system, and did not adopt the new calendar until 1752. George Washington was born on February 11, 1732, but after 1752 his birthday bacame February 22, which is now officially Washington's Birthday. ==================================================================== Puzzle 30 Solution Wet Dreams Pick up pail number 2 and pour it into pail number 5, put it back in place. ==================================================================== Puzzle 31 Solution Saved by the Bell 4, 1, 5, 1 These are how many times a clock strikes, beginning at midnight. ==================================================================== Puzzle 32 Solution Counting on You Reversed alphabetically. ==================================================================== Puzzle 33 Solution Trees in the Forest In a star pattern: * * * * * * * * * * ==================================================================== Puzzle 34 Solution Woof! ------------------- | W / W \ W | | /_______\ | | / | |\ | |/ | | \| | W | W | W | |\ | | /| | \ |________|/ | | \ / | | W \ W / W | ------------------- ==================================================================== Puzzle 35 Solution One Level Harder \ | \ | \ * *-----*-----* | |\ | | \ * * \* * | | \ / | | / * * */ \* | | / \ | | / \ * */----*-----*----\ | / | / / ==================================================================== Puzzle 36 Solution You Would Think You Couldn't Do It There is not a single letter "e" in the entire paragraph, the English languages most common letter. (the title either) ==================================================================== Puzzle 37 Solution Strict Terms Zero. (the (x-x) term of the equation equals zero, which, when multiplied against the rest of the terms, zeros out everything) ==================================================================== Puzzle 38 Solution A Bumpy Problem He added his camel to the herd, to give a total of 18 camels. 1/2 to the oldest son was 9 camels, 1/3 to the second son was 6 camels, and 1/9 to the youngest son was 2 camels, for a total of 17 camels, and the wise man rode away on his camel. ==================================================================== Puzzle 39 Solution Burning Bright Light three ends at once. You take String A, light both of its ends. You take String B, and light one end. Because you lit both ends of the first string, in a half an hour's time, that string is going to burn up completely. A half an hour has gone by, and the other string you lit is going to burn for half an hour's time. As soon as the first string has burned up completely, you'll light the remaining end of String B, and because the first part of that string you lit is continuing to burn, it's going to take 15 minutes before those two flame fronts meet, and you'll have measured exactly 15 minutes (from the time that you lit the second string). ==================================================================== Puzzle 40 Solution Joe Hoofs it Home Fifty minutes. Because if they arrived home 20 mintues earlier than usual, he saved, by walking, 10 minutes of her travel time to the station and 10 minutes of her travel time from the station. Therefore, he was walking for 50 minutes when she picked him up. ==================================================================== Puzzle 41 Solution The Prisoner's dilemma The prisoner can improve his chances from 50/50. If he rearranges the marbles, putting 99 marbles in one box and 1 white marble in the other box, his chances are improved. ==================================================================== Puzzle 42 Solution Armored Planes What he noticed was that the planes that returned, the surviving planes, indeed had bullet holes all over the place, but he figured that the ones that didn't return had bullet holes where these planes didn't have bullet holes. So, what his recommendation very simply was, armor plate the unhit areas that the returning or surviving planes had in common. When he surveyed the undersides of these, he noticed that there were a few spots that all of them had in common that had no bullet holes. And he had to assume that the ones that hadn't returned had been hit in those areas. ==================================================================== Puzzle 43 Solution Boy, oh boy. In the first case 1 in 3, in the second case, 1 in 2. In the first case, numbers 1, 2 and 3 all are possibilities (one boy), but out of those 3 possibilities, only number 1 allows for the other to be a boy (1 in 3). In the second case, only numbers 1 and 2 fit the bill (oldest child a boy), and out of those possibilities, only number 1 allows for the other to be a boy (1 in 2). 1. Boy / Boy 2. Boy / Girl 3. Girl / Boy 4. Girl / Girl ==================================================================== Puzzle 44 Solution One Lump or Two? He reaches into the jar. He pulls out a crumpled piece of paper. He uncrumples it. And he reads on it, "Death". A big smile comes across his face. He immediately stuffs the piece of paper in his mouth, chews it and swallows it. Dancing around the room, he says, "Oh my God, I can't believe my good fortune." Everyone says, "What did it say?" He says, "Ask the King what it says on his slip of paper and you'll know what mine said." The King has to show his piece of paper that says, "Death", so, the other one must have said, "Princess." ==================================================================== Puzzle 45 Solution A rose is a rose They are best known by their middle names. Hiram Ulysses Grant (he added the "S" for Simpson later on in life) Joseph Rudyard Kipling Thomas Woodrow Wilson Stephen Grover Cleveland John Calvin Coolidge. ==================================================================== Puzzle 46 Solution Eating Your Way to Knowledge On a book shelf the first page of the first volume is on the "inside" __ __ B| | | |F A|1 |...........................|10|R C| | | |O K| | | |N | | | |T ---------------------------------- so the bookworm eats only through the cover of the first volume, then 8 times 1000 pages of Volumes 2 - 9, then through the cover to the 1st page of Vol 10. He eats 8,000 pages. If the bookworm ate the first page and the last page, it ate 8,004 pages. ==================================================================== Puzzle 47 Solution Prime Cuts Two. OOO C OOOOO C OOOOOOOOOOO (where Os are chained unbroken links, and the Cs are the unchained broken links) And equivalently: OOO C OOOOOO C OOOOOOOOOO ==================================================================== Puzzle 48 Solution Lock, Stock and Box Attach a lock to the ring. Send it to her. She attaches her own lock and sends it back. You remove your lock and send it back to her. She removes her lock. =================================================================== Puzzle 49 Solution In Rhyme The puzzler tried to take the test; Intriguing rhymes he wished to best. But "Fifty and ten dozens twenty" made his headache pound aplenty. When he finally found some leisure, He took to task this witty treasure. "The product of the age must be Twenty-Four Hundred Fifty!" Knowing that, he took its primes, permuted them as many times as needed, til he found amounts equal to, by all accounts, twice the Verger's age, so that He would have that next day's spat. The reason for the lad's confusion was due to multiple solution! Hence he needed one more clue to give the answer back to you! Since only one could fit the bill, and then confirm the priest's age still, the eldest age of each solution by one could differ, with no coercion. <=(Sorry) Else, that last clue's revelation would not have brought information! With two, two, five, seven, and seven, construct three ages, another set of seven. Two sets of three yield sixty-four, Examine them, yet one time more. The eldest age of each would be forty-nine, and then, fifty! With lack of proper rhyme and meter, I've tried to be the first completor of this poem and a puzzle; my poetry, you'd try to muzzle! And lest you think my wit is thrifty, The answer, of course, must be fifty! If dispute, you wish to tender, note my addresss, as the sender! ================================================================ Problem 50 Solution Top Secret The answers given were the the number of letters in the question. When asked "Nine?" the secret agent should have answered "Four". ================================================================ Problem 51 Solution The Mountaineer Of course there is. To make sure, imagine two mountaineers: one is in the village, and the other one is at the refuge. They'll both leave at eight o'clock, travel along the same path as our mountaineer, and at his same speed. At some point along the path they'll obviously meet. ================================================================ Problem 52 Solution The Desert Crossing Chad, I think this is the answer - check it. 334 First trip carries 1000, goes 333 miles, drops 334 bananas, walks back 333 miles (1000 bananas total) Second trip carries 1000, goes 333 miles, picks up 333 bananas, walks 167 miles (to the 500 mile point), drops 334 bananas (leaving him with 499), walks back 500 miles picking up the single banana on the way to make the 500 he needs to get back. Third trip, 1000 bananas takes him across the desert, picking up the 334 bananas at the halfway point. ================================================================ RAY: Yeah. You've been placed on a medication regime in which you are to take the following medications once a day. You are to take one tablet of medicine A and one tablet of medicine B. TOM: That would be like Valium and Prozac. RAY: There you go. In your case, right. TOM: In my case. RAY: So, you've got two little boxes of pills, and you must be careful, because taking two or more Bs can have unpleasant side effects, like severe hemorrhoidal flare-ups. And taking an A and not a B, or vice versa, can also be very serious. TOM: Mmm-hmm. RAY: So, in order for B to be effective, it must be accompanied by the A pill, so you must take exactly one A and one B. Got it? TOM: I'm with you. RAY: So, you open up the A bottle, and you tap it, and one A pill falls into your hand. TOM: Got it. RAY: You put that bottle aside and you take the B bottle. You do the same, but by mistake, two Bs fall into your hand. Now, here's the problem. The pills look identical. TOM: Oh, bummer! RAY: Same size, same weight, same color, same everything. And they don't have As and Bs written on them, and they're both identical, so what are you gonna do? You can't tell which is which, but if you go eenie, meenie, minie, moe. TOM: You could throw them away and start over again. RAY: But, ah! They're a hundred bucks apiece. Did I mention that? TOM: You can't throw them away and start over again. RAY: So, here's the question. How do you get your daily dose of exactly one A and exactly one B without wasting any of the pills? TOM: Wow! RAY: And here's how you do it. You know that you have one A and two Bs. You just can't tell which are which. So let's add another A to the mix. So now, you have two As and two Bs, so you lay the four pills out in a row. But you don't know which are which. TOM: No. RAY: Now, you could again go, eenie, meenie, minie, moe. And your chances of getting the right thing are improved by having done this, but not good enough. TOM: No, because you might die. RAY: You could die. However, if you take each pill and cut it in half and without mixing up the halves, in other words, the first pill you cut in half, you leave those two halves near each other. TOM: Yeah. RAY: And the same thing with the second, the third, and the fourth pill. And then you take one from each of the cut pills. TOM: A half a pill from each of the pairs. RAY: Right. So, by definition, because you know you have two As and two Bs in the mix, you'll take a half an A from one of the cut pills, and a half a B, and then another half an A, and then another half a B, and you'll have two half Bs and two half As, making one A and one B, and then the remaining pills, cut pieces, will be tomorrow's dose. ================================================================ AY: Three guys go out fishing. They decide in advance that whatever they catch, they're going to divvy it up equally. TOM: Was this a motorized boat or a sailboat? RAY: This was a sailboat, because this is a non-automotive question. RAY: They finish fishing for the day, pull back into port, and go to sleep on the boat, with plans to divvy up the fish in the morning. In the middle of the night, however, one of the guys has a severe hemorrhoidal flare-up, and he's got to get to the drugstore right away to buy some Preparation H. So, he goes to take his third of the fish, and he notices that the number that they caught is not divisible by three, unless he throws one of the fish overboard, which he does. Then, he takes his third and leaves. A few hours later, in the middle of the night, another guy wakes up with horrible stomach pains, and realizes that he's got to get some Kaopectate. So, he goes to take his third, and he notices, interestingly, that he, too, can't take a third unless he throws one fish overboard. He throws one fish overboard, takes his third, and goes home. Finally, the third guy, whose stomach is fine, and whose hemorrhoids have not flared up, gets up in the morning, realizes that he hasn't taken his third of fish, but he's got to go home anyway. However, he can't take a third. TOM: Let me guess! Not divisible by three. RAY: Sonja Henie's tutu! What are the chances of that? He throws one fish overboard, takes his third, and leaves. What is the smallest number of fish by which this little scenario could have taken place? ================================================================ ================================================================