What is the probability that Chris will get the favorite parking spot on three different days in one week?

Question

Chris arrives at work at the same time all five work days. Chris has a favorite parking spot. The
probability that Chris will get the favorite parking spot is 70% every day that Chris works.
What is the probability that Chris will get the favorite parking spot on three different days in
one week?

Answer 1

Use the binomial distribution.

 

P(3) = C(5,3)(.7)³(1-.7)² = 10 * .343 * .09 = .3087

Note: in Excel, you can use =BINOM.DIST(3,5,0.7,FALSE)