Mathematicians have worked out a fail-safe strategy to win at the game Guess Who.
You'll know the famous board game: two people trying to guess which character their partner is thinking of from a series of 24 different-looking options.
David Stewart is a mathematician at the University of Manchester. He's part of the group that devised this new strategy, and he speaks to Mark Leishman.
Give the strategy a go on their online model.
Stock photo Photo: 123RF
