A small lake haves 50 fish. One day a fisherman catches 10 of these fish and tags them so that they can be determined if they're caught again. The tagged fish are released back in the lake. The next day the fisherman goes out and catches 8 fish, which are kept in the fishing boat till they're all released at the end of the day.
a. Compute the probability that 3 tagged fish are caught on the second day?
b. Determine the expected number of tagged fish recaptured on the second day.