The table below indicates the law of probability concerning the potential winning prizes offered by the tane store as part of its lottery. Lot( in $) Probability 0 0.45 10 0.3 100 0.2 500 0.05 If a customer buys a single ticket. a) What is the probability that he wins exactly $100? b) What is the probability that he wins at least $10? c) What is the probability that he wins no more than $100? d) What is the average gain that this customer can expect by buying a ticket?