"Hearst Magazines and Yahoo may earn commission or revenue on some items through these links." Researchers at Duke University monitored participants’ brain activity while they completed simple math ...

Add Yahoo as a preferred source to see more of our stories on Google. Who doesn't love a clever brain teaser puzzle? Also known as rebus puzzles, these visual brain teasers will challenge your wits!

A fun and surprising challenge comparing footballers and random number thinking to see who performs better under pressure.

Only sharp minds can solve this matchstick puzzle in 21 seconds. Move one stick, think creatively, and see if you can find ...