Answer: 24 tests
Explanation:
Ms. Carey graded 1/3 of the tests and still had 16 tests to go.
This means that the 16 tests represent the remaining proportion of the total number of tests:
= 1 - 1/3
= 2/3
2/3 of the total is equal to 16 tests. Assuming the total is x, the expression would be:
2/3x = 16
x = 16 ÷ 2/3
x = 16 * 3/2
x = 24 tests