TheNightKing wrote:
P, Q and R are 3 small pumps fitted to a tank. S is a large pump fitted to the tank. Q is 50% more efficient than P. R is 100/3% is more efficient than Q. S is 50% more efficient than R. All of the pumps are used to fill the tank.
What is the ratio of the time taken by pumps P and R to fill the tank together to the time taken by pumps Q and S to fill the tank together ?
A. 3 : 2
B. 4 : 3
C. 2 : 3
D. 3 : 5
E. 3 : 4
Avoid fractions by assuming a convenient value for the rate of P. Say it pumps 4 lt/sec.
P = 4 lts/sec
Q = 50% more efficient than P = 6 lts/sec
R = 100/3% more efficient that Q = 8 lts/sec
S = 50% more efficient than R = 12 lts/sec
Rate of P and R together = 4 + 8 = 12
Rate of Q and S together = 6 + 12 = 18
Ratio of rates of P and R : Q and S = 2:3 so ratio of time taken by them will be inverse i.e. 3 : 2.
Answer (A)
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Karishma
Veritas Prep GMAT Instructor
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