Please help with this one

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?

Select the number of ways in which a line and a circle can intersect

What number gives you a irrational number when added to 2/5