Week 1
10-digit number
"I have not failed, I've just found 10,000 ways that won't work" - Thomas Edison |
Week 2
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Week 3Can you just smell that? It's the smell of brains hard at work. We're at it again, today we're going to help the painter.
Scott the painter is going to paint the floors of 16 rooms. He is in room #1. He can go through any door (see diagram). He cannot return to any room once he has painted it — slow drying paint! In what order should he paint the rooms? Obviously, #16 must be last. 
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Week 43 men go into a hotel. The man behind the desk says a room is $30 so each man pays $10 and goes to the room.
A while later the man behind the desk realized the room was only $25 so he sent the bellboy to the 3 guys' room with $5. On the way the bellboy couldn't figure out how to split $5 evenly between 3 men, so he gave each man a $1 and kept the other $2 for himself. This meant that the 3 men each paid $9 for the room, which is a total of $27 add the $2 that the bellboy kept = $29. Where is the other dollar? |
Week 5You are standing by the duck pond with two pails. One holds 7 gallons and the other holds 3 gallons. Neither one of them has gallon markings on the side. How can you get exactly 5 gallons of water in the big pail?
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Week 6Queens in chess can "attack" in every linear direction. That is, a queen is considered to be "attacking" any piece which is on the same row, column or diagonal as the queen.
Can you place 8 queens on an 8x8 chessboard such that no queen is attacking any other queen? |
Week 7
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Week 8A chicken farmer has figured out that a hen and a half can lay an egg and a half in a day and a half. How many hens does the farmer need to produce one dozen eggs in six days?
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Week 9Tony goes into Dave's Army-Navy store and buys a hat for $14. He gives Dave a $20 bill. Dave doesn't have any change, so he takes the $20 bill across the street to Laura, the clerk in Watson's Hardware store. Laura trades Dave's $20 bill for twenty $1 bills. Dave comes back and gives Tony $6 in change. Tony takes the hat and the $6 change and leaves town forever. Half an hour later Laura comes over to Dave’s store, just furious. She has discovered that the $20 bill he gave her is counterfeit. Dave, of course, makes it good, giving Laura a genuine $20 bill he has in the till from an earlier sale. Question: Now that it is all over, who came out behind? And by how much?
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Week 10Create a Magic Square of 18:
All 3 rows add up to 18. All 3 columns add up to 18. The 2 diagonals add up to 18. There are 8 lines, each totaling 18. In this magic square, numbers from 2 to 10 are used AND not repeated. Example of a magic square of 15 
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Week 11How can you add eight 8's to get the number 1,000? (only use addition)
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Week 12Two fathers and two sons sat down to eat eggs for breakfast. They ate exactly three eggs, each person had an egg. The riddle is for you to explain how.
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Week 13Eight adults and two children need to cross a river, and they have one small boat available to help them. The boat can hold either one adult, or one or two children. The boat cannot hold an adult and child. Everyone in the group is able to row the boat. Show how you get them all across the river.
How many one-way trips does it take for the eight adults and two children to cross the river? |
Week 14
Your First Choice
You are confronted by 3 doors. Behind one of them is a car, behind the two others, you will only see a goat. Now, if you correctly pick the car, you win the car ! Otherwise, if you get one of the 2 goats, you don't get the car. So, pick any door. It doesn't matter which one, but we will suppose that you picked door #2, as an example. 
Should You switch?
Now, after you have picked a door and before finding out what is actually behind it, you are shown a goat behind one of the other doors. (Remember there has to be a goat in 1 of the doors that you have not picked.) Let's say you choose door #2, as shown above. For example's sake, let's say there's a goat in door 1. The question and the riddle is : should you switch the door that you picked? In other words, in this example, should you now choose door 3? Or, should you stick with your first choice (door #2)? |
Week 15 |
Week 16 |
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A farmer returns from the market, where he bought a she-goat, a cabbage and a wolf (what a crazy market :-). On the way home he must cross a river. His boat is small and won't fit more than one of his purchases. He cannot leave the she-goat alone with the cabbage (because the she-goat would eat it), nor he can leave the she-goat alone with the wolf (because the she-goat would be eaten).
How can the farmer get everything on the other side in this river crossing puzzle? |
An insurance salesman walks up to a house and knocks on the door. A woman answers, and he asks her how many children she has and how old they are. She says I will give you a hint. If you multiply the 3 children's ages, you get 36. He says this is not enough information. So she gives him a 2nd hint. If you add up the children's ages, the sum is the number on the house next door. He goes next door and looks at the house number and says this is still not enough information. So she says she'll give him one last hint which is that her oldest of the 3 plays piano.
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Week 17Given a 5-liter jar and a 3-liter jar and an unlimited supply of water, how do you measure out 4 liters exactly?
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Week 18 |
