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
