Question

Mr. Coelho and Ms. Steiner are grading math and science tests of sixth-grade and seventh-grade students, respectively,

Mr. Coelho graded 25 science tests in 50 minutes and 30 math tests in 40 minutes. Ms. Steiner graded 20 science tests in
50 minutes and 12 math tests in 30 minutes.
Whose grading shows a proportional relationship between the number of tests graded and the time spent grading?

The answer is only ms.Steiner’s grading

Answer 1

Ms. Steiner

Explanation:

Mr. Coelho

science = 25 / 50 = 1/2

math = 30 / 40 = 3/4

not the same rate

Ms. Steiner

science = 20 / 50 = 2/5

math = 12 / 30 = 2/5

It is the same rate, so they are proportional

Answer 2

Mr. Coelho: Science: 50 minutes / 25 tests = 2 minutes per test

Math: 40 minutes / 30 tests = 1.33 minutes per test.

Ms. Steiner: Science: 50 minutes / 20 tests = 2.5 minutes per test.

Math: 30 minutes / 12 tests = 2.5 minutes per test.

The answer is Ms. Steiner.