## The Monty Hall Problem Explained

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…

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 two different solutions. In matchstick equation puzzles, you are not allowed to make an inequality symbol such as ≠, ≥, >, <, or ≤. That would make it…

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…

What can go through towns and cities, over hills and mountains, but never moves?

What two numbers contain no zeroes and can be multiplied together to produce 100000?

Some consider Friday the 13th (any Friday that falls on the 13th day of a month) unlucky. In a calendar year, how many Friday the 13th can occur? Find both the minimum and maximum.

Two ferry boats serve the same route on a river, but travel at different speeds. They depart from opposite ends of the river at the same time, meeting at a point 720 yards from the nearest shore. When each boat…

Given the iterative formula: xn+1 = sqrt(xn) + a There are some values of a for which a positive starting value for x results in this formula converging to an integer. For example, if a = 2, you would observe…

Find a combination of three different positive integers x, y, and z such that: x3 + y3 = z4 Hint: there’s a better way than brute force / trial & error.