How much of your GCSE maths knowledge can you remember?
Let's be honest, most of us haven't even thought about most of the stuff we were taught in maths since we left school. You might have to do the occasional quick sum in the supermarket, but how often do you really use algebra and more specific sums like working out the area of something? Well, if you want to solve this latest brain teaser, you'll have to cast your mind back to when you were at school and hope you can pull the knowledge out from the depths of your brain.
The question was aired during an episode of Michael McIntyre's The Wheel last month, and it left the contestant, a woman named Karen, completely stumped. But could you solve it?
The question Karen was asked was this: "If the radius of the wheel is six metres, what is the area of the whole wheel?"
In the show, seven celebrities are designated as experts of a single subject, and when contestants choose a subject, they also get to "shut down" one celebrity that they don't want to help answer the question. Then the wheel is spun, and whichever celebrity it lands on, the contestant has to help them with a multiple choice question.
'Impossible' maths question that stumps all parents as well as kidsDespite maths being Rachel Riley's specialist subject, Karen wasn't lucky enough for the wheel to land on her, and she instead had the help of Gabby Logan - who was just as baffled as the contestant.
To help the pair get to an answer, they were given four options - 43 square metres, 63 square metres, 93 square metres, or 113 square metres. Do you know what the answer is?
You'll need to know the right formula to use to work this one out, and it's not as easy as it looks. You might know that the radius is half the diameter of a circle, but do you know what to do once you've worked that out? Karen and Gabby had no idea, and in the end, they guessed the answer. Karen said: "It's going to be a guess of 113 square metres."
Building up suspense, Michael joked at the pair for having said "many many words that you've heard in maths" before finally taking a complete stab in the dark with their answer. But was their guess right?
Answer
Yes, the answer really was 113 square metres. After the answer was revealed, Michael asked expert Rachel Riley for an explanation, and she said: "So the radius is half the diameter. The area of a circle is pi R squared (πr2). The radius squared is 36 [6x6] times by pi which is 3.142. 3 x 36 is 108 and then you need to add on a little bit more, and that [113] was the only one bigger."
Did you get the answer right? Let us know in the comments. And if you want to try your hand at some other quiz show questions, this Pointless question was dubbed the 'most difficult' as contestants were left baffled.
There are also different types of puzzles you can try, such as this fiendishly difficult quiz shared by the question editor for BBC Two's Only Connect, or this maths equation that is said to be so tricky that only those with the IQ of Albert Einstein can solve it, or even this Who Wants To Be A Millionaire jackpot question that saw one contestant miss out on £1 million.