Question

A science test, which is worth 100 points, consists of 24 questions. Each question is worth either 3 points or 5 points. If x is the number of 3-point questions and y is the number of 5-point questions, the system shown represents this situation. x + y = 24 3x + 5y = 100 What does the solution of this system indicate about the questions on the test? The test contains 4 three-point questions and 20 five-point questions. The test contains 10 three-point questions and 14 five-point questions. The test contains 14 three-point questions and 10 five-point questions. The test contains 20 three-point questions and 8 five-point questions.

Answer 1

B, The test contains 10 three-point questions and 14 five-point questions.

Explanation:

x + y = 24

3x + 5y = 100

1. Rearrange the first equation to isolate either x or y.

x = -y + 24

2. Plug this new equation into the second equation to find the value of y.

3(-y + 24) + 5y = 100

-3y + 72 + 5y = 100

2y + 72 = 100

2y = 28

y = 14

3. Plug the value of y back into the other equation to find the value of x.

x = -14 + 24

x = 10

There are fourteen 5-point questions and ten 3-point questions.