Can you solve this seemingly simple algebra question?
If you were paying attention during your maths lessons at school then you should have no trouble solving the question.
The image has been share and liked by more than 70,000 Facebook users and has attracted a whopping 480,000 comments.
Many have been arguing about the correct answer – so what do you think it is?
An explanation on suggests the answer must be 21
Many mathematicians use the acronym BODMAS to solve such riddles. It stands for Brackets, Orders, Division, Multiplication, Addition, Subtraction.
B
Brackets first
O
Orders (i.e. Powers and Square Roots, etc.)
DM
Division and Multiplication (left-to-right)
AS
Addition and Subtraction (left-to-right)