These lying thief riddles are fun and tricky logic puzzles that will test your brain. In each puzzle, you interrogate a number of suspects, knowing that some of them are lying, and use that information and your deduction skills to…
White to play and mate in 2
Whether you’re preparing for an interview or just trying to keep your mind sharp, here are some quant brain teasers to test your skills. Remember, if you get a brain teaser at an interview, you don’t necessarily need to get…
In a certain classroom, 75% of the students can speak English, 55% of the students can speak French, and 10% speak neither language. What percentage of the students speak both languages?
The shaded rectangle is tangent to the circle at the two points indicated, and its bottom right corner lies on the circumference of that circle. What is the area of the rectangle?
Ava, Beth, Cam, and Derek each have a different favorite fruit and favorite color. We know their favorite fruits are apple, banana, cherry, and durian, and their favorite colors are blue, green, red, and yellow. We also know: What is…
The Monty Hall Problem You are on a game show in which there are three identical doors, one with a car behind it and two with goats behind them. You must pick one door, and you win if that door…
In matchstick puzzles, you are presented with an incorrect equation made using matchsticks, and you must move 1 or more matchsticks to turn it into a valid equation. You must use all of the matches, and you are not allowed…
There is a bag with 20 blue balls and 13 red balls. Randomly remove 2 balls from the bag: Repeat this process until there is just 1 ball remaining. What is the color of the last ball?
Do some creative thinking and try to solve these 10 clever riddles: Riddle #1 What do you usually have to break before you can use it? Riddle #2 What do you need to answer even though it never asks a…
Move exactly 2 matches to make this a valid equation. Bonus: find more than one solution. In matchstick equation puzzles, you are not allowed to make an inequality symbol such as ≠, ≥, >, <, or ≤. That would make…
A rebus is a puzzle in which words, objects, or symbols are arranged in a way to indirectly represent a commonly known word or phrase. Solving rebus puzzles can be a fun and easy way for kids to think both…
White to play and mate in 2.
If a triangle has two sides with lengths 3 and 4, what should the length of the third side be in order to maximize the area of the triangle?
Compound words are words that are composed of two or more other words, like high + light = highlight. Can you make compound words out of the following three words by adding the same 4-letter word either before or after each word?
Prove that for all prime numbers p > 3, (p2 – 1) is a multiple of 24.
What is the most frequent digit among the numbers between 1 and 1000 (inclusive)? Consider only base-10 whole numbers.
There is a long line of people waiting to see a new movie. They announce that the first person to have the same birthday as someone standing before them in the line gets to meet one of the actors in…
A prison warden was feeling capricious and played a game with the prison keys: What is the fewest number of days it would take for the prisoners to be sure everyone has their key? What was the strategy to achieve…
The digital sum of a number is just the sum of the individual digits. E.g., the digital sum of 123 is 1 + 2 + 3 = 6. What is the digital sum of z = x + y?
If you have me, you want to share me. If you share me, you haven’t got me. What am I?
In this sharing game theory puzzle, 3 friends take turns taking from a jar of 1000 candies to share. For example, the 1st friend could take 500 candies, then the 2nd friend could take 400, and the 3rd friend would…
I am a 5-letter word. I am normally below you. If you remove my 1st letter, I am normally above you. If you remove my 1st and 2nd letters, I am all around you.
What common word or phrase is this rebus referring to? || READ ||
A rock paper scissors puzzle: Anya played 10 games of rock paper scissors against Blake Each time there was a winner (no ties) Anya used rock 2 times, paper 2 times, and scissors 6 times, but you don’t know the…