A deceptively simple maths puzzle has been circulating online, leaving thousands of people second-guessing themselves. The question involves a man buying and selling a goat — twice — and asks how much profit he made in total. The answer is simpler than most expect.

The riddle is straightforward on the surface: a man buys a goat for $60, sells it for $70, buys it back for $80, and sells it one final time for…

