## 15 Interesting Brain Teasers to Challenge Intelligent Engineers

Included in this challenging list are puzzles that aspiring astronauts must complete in order to be selected for training.

## 13 Stimulating Brain Teasers, Logic Questions, and Optical Illusions

Can you take on this tricky list of brain teasers, including riddles by Albert Einstein, without making a single mistake?

## You're a Genius if You Can Finish These 13 Brain Teasers Without a Mistake

Brain teasers, riddles, optical illusions, and puzzles are a great way to keep the mind alert.

## A Modern-Day Treasure Hunt: Cracking Cicada 3301

A primer on what you need to know about the internetâ€™s greatest puzzle.

## Human Q&A with AI Displays Computer-Generated Thinking Weaknesses

Understanding how computers process their answers has revealed how us humans can stump them with certain questions.

## Simple Math Equation Divides Internet

The equation sent the internet into a frenzy over who had the right answer. Can you solve it?

## 7 Things We Still Don't Know About Our Vast Oceans

Here are the mysteries kept by the seven seas!

## Numberphile Explains the Unsolvable Graceful Tree Problem

Watch the math expert try and fail to solve the conundrum that has been around since 1967.

## This Video Introduces the Most Unexpected Answer to a Counting Puzzle

This problem Grant Sanderson (3Blue1Brown) calls both the most elegant and the most comically inefficient is guaranteed to have you working overtime to solve it.

## Try and See If You Can Solve This Challenging Broom Riddle

This fun puzzle involves a broom's center of mass and an estimation of each of its sides' weights.

## UK Mathematician Teases Internet With Tricky Math Problem

A mathematics professor took to Twitter to pose a puzzle to his followers. Math lovers from everywhere united to step up to the challenge.