Question

A student is told to work any 8 out of 10 questions on an exam. In how many different ways can he complete the exam

Answer 1

Explanation:

Assuming the order in which he answers the questions matter the answer is the number of permutations of 8 in 10.

This is 10! / (10-8)!

= 1,814.400.

If the order does not matter then the answer is the number of combinations of 8 from 10:

This is 10!/8!*2!

= 45.