A Store Is Offering a Discount on 800 Pairs of Basketball

Essay

A store is offering a discount on 800 pairs of basketball shoes. The amount of the discount varies and is not revealed to the customer until checkout. The distribution of discounts is given in the below table. $$\begin{array}{l}\begin{array} { c c } \text { Discount Rate (\%) }&\text {Number of Tags }\\5 & 250 \\20 & 220 \\35 & 120 \\50 & 80 \\65 & 70 \\90 & 60\end{array}\end{array}$$ How many pairs of shoes does a customer have to buy so that, on average, he has purchased five containing a 65% or 90% discount? (Hint: Use the hypergeometric distribution in ASP to answer this question.)