EEPhil
Number 28
The original question needed a second part. If the area is (some sensible number) cm^2, what is X? If they couldn't do the first part, the second part would really have them foxed. (And they could do part 2 without part 1 given the form of the question.)Deriving an equation (which doesn't then require a solution) means the little darlings aren't even taxed with the quadratic formula!