A maths question posted on Facebook has divided users who can't agree on the answer to what looks like a simple sum.
The teaser, posted three weeks ago has nearly 600k comments with users offering a selection of possible answers.
They can't all be right.
The confusion is mostly caused by users forgeting to apply Bodmas rule – Brackets, Order, Divide, Multiply, Add and Subtract – the sequence of operations of arithmetic
If you want to know the correct answer, and how to get it, then watch the explainer video below.