1. A local drugstore owner knows that, on average, 20 people enter his store eachhour, assume that the number of people that come into the store follows a Poissonprocess.

(a) Find the probability that at least 10 people will come to the store in 30 minutes.

(b) Find the probability that at least 5 people will come to the store in 15 minutes.

2. A store has 20 guitars in stock but 3 are defective. Claire buys 5 guitars from thislot.

(a) Find the probability that Claire bought 2 defective guitars.

(b) Suppose that 3% of a total of 5000 guitars are defective. Claire buys 10 guitarsfrom this lot. Find the probability that Claire bought 2 defective guitars from this lot.

3.It is estimated that 5 out of every 8 houses give away candy for Halloween.

(a) If we want to receive candy from 5 different houses, what is the probability that we will need to visit at least 10 of them?

(b) If you plan to visit 26 houses, what is the probability that you will get candy in at least 15 of them?