65 % ------------------ 23.4 items 100 % ----------------- x items 65 : 100 = 23.4 : x 65 x = 100 * 23.4 65 x = 2340 x = 2340 : 65 x = 36 Answer: there were 36 items on the test.
They didn't make it easy. Grid lines are apparently 3 apart, but the offered coordinates are all multiples of 4. It appears the only point that is in the doubly-shaded area is ...