Working at constant rate, pump X pumped out half of the water in a flooded basement in 3 hours. The pump Y was started and the two pumps, working independently at their respective constant rates, pumped out rest of the water in 3 hours. How many hours would it have taken pump Y , operating alone at its own constant rate, to pump out all of the water that was pumped out of the basement?  Pick:
A) a. 20
B) b. 12
C) c. 14
D) d. 18
E) e. 24
rate of x=1/8   rate of x+y=1/6   rate of y=1/6-1/8=1/24   20 hours   a. 20
<result>A</result>
Working at constant rate, pump X pumped out half of the water in a flooded basement in 3 hours. The pump Y was started and the two pumps, working independently at their respective constant rates, pumped out rest of the water in 3 hours. How many hours would it have taken pump Y , operating alone at its own constant rate, to pump out all of the water that was pumped out of the basement?