Two water pumps, working simultaneously at their respective constant rates, took exactly 8 hours to fill a swimming pool. If the constant rate of one pump was 1.5 times the constant rate of the other, how many hours would it have taken the faster pump to fill the pool if it had worked alone at its constant rate?	Choose the correct choice from the following answers.
A) 28/3
B) 32/3
C) 35/3
D) 40/3
E) 44/3
Let the rate of the slow pump be x. Then the rate of the fast pump is 1.5x.   (x+1.5x) = 2.5x = 1/8 of the capacity of the whole pool per hour.   The rate of the fast pump is (1.5/2.5)*1/8 = 3/40 of the whole pool per hour.   The time it takes the faster pump to fill the pool would be 40/3 hours.   The answer is 40/3.
<result>D</result>
Two water pumps, working simultaneously at their respective constant rates, took exactly 8 hours to fill a swimming pool. If the constant rate of one pump was 1.5 times the constant rate of the other, how many hours would it have taken the faster pump to fill the pool if it had worked alone at its constant rate?