Question

Mr.F was given $5 for each test passed but had to return $10 for each test failed. At the end of the first trimester, he passed four times as many tests as he failed, and he earned $20. How many tests did he pass? Explain your thinking.

a. 8 tests
b. 5 tests
c. 4 tests
d. 3 tests

Answer 1

To find the number of tests Mr. F passed, set up a system of equations. Solve the system to find x = 8 and y = 2. Therefore, Mr. F passed 8 tests.

Step-by-step explanation:

To find out the number of tests Mr. F passed, we'll set up a system of equations.

Let x be the number of tests passed and y be the number of tests failed.

From the given information, we know that Mr. F passed four times as many tests as he failed, so we have the equation:

x = 4y

Mr. F earned $20, which is equal to the sum of the money earned from passing tests and the money returned for failed tests. Since he earned $5 for each test passed and had to return $10 for each test failed, we can set up another equation:

5x - 10y = 20

Solving the system of equations gives us x = 8 and y = 2. Therefore, Mr. F passed 8 tests.