An Algebra I test contains 30 questions. Some of the questions are worth 4 points each, and some are worth 2 points each. The total test is worth 100 points. Let f represent the number of questions worth 4 points and t, the number of questions worth 2 points.

Question

Solve the system by elimination to find how many two-point questions the test contains

Answer 1

f + t = 30
4f + 2t = 100

4f + 4t = 120
4f + 2t = 100

2t = 20
t = 10
So, f = 20