Only ‘smart’ people can solve brain teaser which has ’caused a lot of arguments’

How good are you at maths? Apparently only those who are really smart can solve the below puzzle, and it’s caused a lot of arguments – give it a go and see how you doHow good are you at maths? Apparently only those who are really smart can solve the below puzzle, and it’s caused a lot of arguments – give it a go and see how you do