Mr. Rivera can grade 18 math teat in 15minutes. What is the teachers unit rate?

In this question, you're trying to find the unit rate in which the teacher can grade tests.

A unit rate is another word for "rate of change".

This means that we have to find how many tests the teacher could grade in 1 minute.

To find the unit rate, divide 18 by 15

18 : 15 = 1.2

This means that Mr. Rivera can grade 1.2 tests in 1 minute.

Answer:

1.2 tests