Question

Problem 4 A father brings his two children to a pet store to buy them comet goldfish. When they arrive, they find that the store has a tank filled with exactly 1,024 individual comets. The father reasons that he should buy each child four comets in order to improve the odds of each child getting at least one long-living pet, as comet goldfish are cheap feeder fish that are being kept in poor conditions at the store. Determine the following:

a) How many ways can the father select four comets for each of his two children?

b) If 75% of the comets in the tank are infected with some life-threatening parasite, how likely is it that all of the fish that the father selects will have this parasite?

c) If 75% of the comets in the tank are infected with some life-threatening parasite, how likely is it that half of the fish that the father selects will have this parasite?

Answer 1