Balloon Direction Puzzle
You are driving your niece to a birthday party, and she is bringing a floating balloon filled with helium. When you make a sharp left turn, you both shift to the right. Which way does the balloon shift? Assume the…
Pirate Survivor Puzzle
The democratic pirates are at it again! Since last time, they have become very successful and have now expanded to 100 pirates. They decide this is too large of a group for plundering, so true to their democratic roots, they…
Rebus Puzzle 5 – MOONCEON
What common word or phrase is this rebus referring to? MOONCEON
Crouching Tiger Chess Puzzle
White to play and mate in two moves.
Sum of Squares
If x is an even integer that can be written as the sum of two perfect squares, prove that x / 2 can also be written as the sum of two perfect squares.
Assess Banana Dresser Grammar Potato Revive Uneven Voodoo
What is a special property or feature that all of the following words have in common? assess, banana, dresser, grammar, potato, revive, uneven, voodoo
Rebus Puzzle 4
What common word or phrase is this rebus referring to? ♣ OFFICE♠ SCHOOL♥ HOME♦ STORE
Handshake Puzzle
Hasan and Lauren attended a dinner party with 4 other couples. Since some people already knew some of the other guests, every person at the dinner party shook hands with every person they had not met before. Lauren noticed that…
Logical List Puzzle
Which logical statement(s) below must be correct? Exactly one statement on this list is incorrect Exactly two statements on this list are incorrect Exactly three statements on this list are incorrect Exactly four statements on this list are incorrect Exactly…
Rebus Puzzle 3
What common word or phrase is this rebus referring to? GIVE GIVE GIVE GIVEGET GET GET GET
Majority Vote Puzzle
After the results of an election, you are told that one candidate has received the majority of the votes, but you don’t know which candidate. You have exactly one opportunity to hear the votes, but: The list of votes is…
Tennis Match Mystery
Abe, Ben, and Catelyn were playing 1-on-1 tennis matches one afternoon. After each match, the winner stayed on the court and the loser was replaced by the person who sat out. At the end of their session, Abe had played…
Equal Piles of Face-up Cards
There is a standard deck of cards, with some cards face-up and the rest of the cards face-down. You are told exactly how many cards are face-up, but you are not allowed to look at the cards. Without seeing which…
Rebus Puzzle 2 – TOUKEEPCH
What common word or phrase is this rebus referring to? T O U K E E P C H
Same Place Same Time
You spend an entire day hiking up a mountain, and camp overnight at the top. The next day, you hike down the mountain along the same trail, starting around the same time you started the day before. How likely is…
Pill Portioning Puzzle
A blind man has to take exactly one green pill and one blue pill each day – no more and no less. However one day he accidentally takes out two pills from the green bottle and two pills from the…
Tale of Two Trains
There are two trains that run between two cities. The trains are identical and run on identical routes, so passengers have no preference between the two and would take whichever train that pulls into the station. The trains run at…
Moving Battleship Puzzle
You are trying to hit a moving battleship, but you have no way of monitoring its position. However, you have the following information: You know where the battleship started. You know when the battleship started moving. You know the battleship…
One Acts Kind at the Spa
Which English word can be added to either the beginning or end of each of the following words, in order to create four valid English words? ONE ACT KIND SPA
Odd Hourglasses
You have two odd hourglasses: one that times exactly 4 minutes and one that times exactly 7 minutes. What is the best way to measure exactly 9 minutes using just these two hourglasses?
Simpson’s Paradox
Simpson’s Paradox (also sometimes known as the reversal paradox or Simpson’s reversal) refers to the phenomenon in which a trend or result that appears in multiple groups of data no longer appears—or in fact reverses—when the groups are combined.
Four Digits Squared
Which perfect square of a 4-digit number has the same last four digits as the original number?
Arrange the Digits
There are 362,880 different ways to arrange the digits 1 through 9 into a 9-digit number. How many of these combinations are prime numbers?
Deducing Bicycle Spokes
A bicycle shop has some number of unusual bicycles. All their bikes are identical (there’s more than one bike), and each bike’s front and back wheels has at least one spoke each (each bike has more than one spoke). You…
Black Red and Gray
What is black when you buy it, red when you use it, and gray when you throw it away?