A jar has 50 balls 1 to 50 each one having distinct number written on it. Bob, owner of the jar,each day he takes out one ball out of the jar randomly ( with equal probability) and put it back.
Q1. How many days on average will it take until all 50 balls are taken out? (Note that the same ball can be picked on more than one days)
Q2. Assume that 3 months after Bob started this activity, how many distinct balls will have been taken out by Bob?