Are you among the top 15% of brainiacs in the country who can solve this math problem? Brainteasers and puzzles are an excellent way to keep your mind as healthy as the rest of your body. They can ...

The original version of this quiz misstated a figure in question two.

Novelist Celeste Ng has shared a head-scratching system of equations that her 9-year-old son apparently made up over dinner: She’s right-using simultaneous equations does get really complicated, and ...