please help thanks

You have 2500 urns, that you place into a 50-by-50 grid. You will throw 60,000 balls (independently) toward the grid of urns, with equal probability for the ball to go in each um. You hope that at the end of the process, each urn will have at least 4 balls inside. You want to upperbound the probability that you will fail to get a] least 4 balls into every urn. (a) Use a Chernoff bound from class to bound the probability that the urn in the lower-left of the grid does not have at least 4 balls inside. [10 points] (b) Is the probability of the lower-left urn having less than 4 balls independent of the probability that the um in the upper-right has less than 4 balls? Briey explain (you may give a formal derivation/calculation as an explanation or an informal one). [3 points] (c) Bound the probability that any urn has fewer than 4 balls. Give the best bound you can from your answers in (a) and (b). [8 points]