For a particular instant lottery, the bettor can determine immediately whether a purchased ticket is a winning ticket. Suppose that the probability of a winning ticket is p=1. 10
a. What is the expected number of tickets that must be purchased in order to find a winning ticket?
b. Find the probability that more than 10 tickets must be purchased to find a winning ticket.
c. Find the probability that exactly 20 tickets must be purchased to find two winning tickets.