Question

There are 18 questions on the test. Each question is worth either four or five points. The total is 80 points. How many questions of each type are on the test?

Answer 1

Answer: the number of four point questions in the test is 10.

the number of five point questions in the test 8

Step-by-step explanation:

Let x represent the number of four point questions in the test.

Let y represent the number of five point questions in the test.

There are 18 questions on the test. It means that

x + y = 18

Each question is worth either four or five points. The total is 80 points. This means that

4x + 5y = 80 - - - - - - - - - - - - - -1

Substituting x = 18 - y into equation 1, it becomes

4(18 - y) + 5y = 80

72 - 4y + 5y = 80

- 4y + 5y = 80 - 72

y = 8

x = 18 - y = 18 - 8

x = 10