How do I solve this inequality!

Students are given 3 minutes for each multiple-choice question and 5 minutes for each free-response question on a test. there are 15 questions on the test, and students are given 51 minutes to take it.how many multiple-choice questions are on the test?

If f(x) = 2x + 2 and g(x) = x? , what is (gºf)(2)?

Use sigma notation to represent the following series for 9 terms.