Question

A student prepares for an exam by studying a list of ten problems. She can solve six of them. For the exam, the instructor selects five problems at random from the ten on the list given to the students. What is the probability that the student can solve all five problems on the exam?.

Answer 1

1/42 = 0.0238

Explanation:

We solve it using combination. for the first part the student can answer 5 questions out of 10 questions given

= 10!/5!(10-5)!

= 252

for the second part the instructor choses 5 questions out 10 for the student to solve.

= 6!/5!(6-5)!

= 6

thus the probability that the student can solve all the problems in the exam is

6/252 = 0.0238