Have you ever come across a math puzzle on social media that seems so easy, yet almost everyone gets it wrong? This classic puzzle claims to be an official interview question from Google. It looks like a simple arithmetic test, but...

A little boy is lying in bed, busting to go to the toilet. So he gets out of bed, runs downstairs into the living room, and finds his mother chatting to a bunch of her friends. "MUM," the boy yells at...