7. A biology class is trying to estimate the number of minnows in Podunk Pond using the capture/recapture method. They set minnow traps around the pond, and minnows enter the traps at a rate of one every 5 minutes. Find the probabilities of the following: a. At least 4 minnows are in a trap after 15 minutes b. At most 20 minnows are in a trap after an hour c. A total of exactly 48 minnows are caught in 4 traps that were left out for an hour each d. A student sets out several traps and then checks each one after it has been out for 20 minutes. What is the probability that the fifth trap she checks is the third one that has more than 5 minnows? 8. Prove P(A") = 1 - P(A)