Two water pomps, working simultaneously at their respective constant rates, took exactly four hours to fill a certain swimming pool. If the constant rate of one pomp is 1.5 times that of the other, how many hours will it take to the fastest pomp alone to fill the pool?
OA later expln
3r/2+2/2 = 5r/2 = combined rate
5r/2(4) = 10r = pool capicity
3r/2 (t) = 10r ==> t = 20r/3