Question

Mark got 14 problems wrong on his test. His score was 72% correct. How many problems were on the test? Please show work.

Answer 1

Consider that 100%-72%=28% represents the percentage of wrong answers. I would think as fractions as:
if 100%  is the total number of answers and 28% are the wrong ones
as
if x is the total you have 14 wrong you can write:
$\frac{100}{28} = \frac{x}{14}$
x=(100/28)*14=50 questions