Brain Teasers and Puzzles

Brain teasers, puzzles, riddles, and other challenges

Algebra, Difficulty - Hard, Number Theory

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.

Difficulty - Easy, Patterns, Sequences, and Sets, Word Puzzles

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

Difficulty - Hard, Rebus

Rebus Puzzle 4

What common word or phrase is this rebus referring to?

♣ OFFICE
♠ SCHOOL
♥ HOME
♦ STORE

Solution

Home is where the heart is

Difficulty - Hard, Interview Brain Teasers, Logic Puzzles

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 everyone else (excluding Lauren herself) ended up with a different number of handshakes!

Can you figure out how many people Hasan shook hands with?

Difficulty - Very Easy, Logic Puzzles

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 five statements on this list are incorrect
Exactly six statements on this list are incorrect
Exactly seven statements on this list are incorrect
Exactly eight statements on this list are incorrect
Exactly nine statements on this list are incorrect

Difficulty - Easy, Rebus

Rebus Puzzle 3

What common word or phrase is this rebus referring to?

GIVE GIVE GIVE GIVE
GET GET GET GET

Click to see solution

Forgive and forget (“four give” and “four get”)

Difficulty - Very Hard, Interview Brain Teasers, Logic Puzzles

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 very long
The votes will be announced one after another in random order
You have a poor memory (can only remember a couple of names or numbers)
You are not allowed to write or record anything

Given these restrictions, is there a way figure out which candidate received the majority of votes?

Difficulty - Hard, Logic Puzzles

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 8 matches, Ben had played 12 matches, and Catelyn had played 14 matches. Ben was particularly exhausted as he had played all of the last 7 matches.

Is it possible to figure out who played and who won in the 4th match?

Difficulty - Medium, Interview Brain Teasers

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 cards are face-up and which are face-down, how can you divide the deck into two piles of cards that contain the same number of face-up cards?

Difficulty - Very Easy, Rebus

Rebus Puzzle 2 – TOUKEEPCH

What common word or phrase is this rebus referring to?

T O U K E E P C H

Solution

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