Question

A test is worth 30 points. Multiple-choice questions are worth 2 point and short-answer questions are worth 3 points. If the test has 13 questions, how many multiple-choice questions are there?

Answer 1

the answer is 9...

2x9=18, 3x4=12, 12+18=30 points, 9+4=13 questions

Answer 2

There are 9 multiple-choice questions and 4 short-answers.

Equations:
2x + 3y = 30
x + y = 13

Plug them in:
2(9) + 3(4) = 30
9 + 4 = 13