10. In how many ways can a student select 7 out of 10 questions to work on an exam

Question

asked May 18, 2022 76.7k views

2 Answers

Hagakurje · Answer 1 · 2022-05-20T12:26:19+0000

7C10 = 10!/(7!)(10-7)!

7C10 = 10!/(7!)(3!)

7C10 = (10 x 9 x 8 x 7)/(7 x 6 x 5)(6)

7C10 = (10 x 9 x 8)/6

7C10 = 720/6

7C10 = 120

Answer: 120 ways