Put your calculators away and get your thinking caps on.
This maths question has been causing headaches up and down the country. It's multiple choice, which makes it a little easier, but it requires a specific piece of mathematical knowledge.
Only one in 80 people get this right, according to the creators of the quiz. Not sure how they've arrived at that statistic, but it's certainly a tricky little bugger of a question.
Give it a go, and even if you have to guess, there's a one in four chance that you'll get it right.
Did you get it? We certainly didn't. For shame.
