A large video rental chain recently decided to change its rental policy, allowing an unlimited
return date instead of requiring that movies be returned the next day. The marketing
team reasoned that this would greatly increase the popularity of their stores, and also that
80% of people would return their movies within 2 days regardless.
a. Suppose that that a specific store has 5 copies of “The Princess Bride”, and rents
them all on a Saturday. What is the probability that all 5 copies are returned by
Monday?
b. The same store rented 250 movies in total that Saturday. What is the probability that
at least 75% of these movies were returned by Monday?
For part a would the solution simply be 0.8^5
and for part b) how would I go about determining 75 % of the movies would it be 187.5 or a whole number 188