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21 Mar 2017, 05:25
Kudos
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C
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93% (00:50) correct
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Two pumps, A and B, are pumping oil out of a reservoir at the same time. If the two pumps are independent of each other, how long would it take to pump all the oil of the reservoir?
(1) Pump A by itself would require half the time that Pump B would require.
(2) Pump A would require 90 hours by itself to pump the reservoir.
(1) Pump A by itself would require half the time that Pump B would require.
(2) Pump A would require 90 hours by itself to pump the reservoir.
21 Mar 2017, 12:12
Kudos
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To solve this we need
1. the Rate at which A and B pumps oil
2. Time taken by A/B to pump the oil by itself or the Total oil in the reservoir
(1) Pump A by itself would require half the time that Pump B would require.
This statement gives only the rate of A and B. But does not give any info on either the Time taken by A/B to pump the oil alone or the Total oil in the reservoir. This statement is insufficient.
(2) Pump A would require 90 hours by itself to pump the reservoir.
This statement gives the time tken by A to pump the oil by itself. But gives no info on the rate of A and B. Hence this statement is insufficient.
combining both statements we get the necessary information to solve this question.
Answer is C
1. the Rate at which A and B pumps oil
2. Time taken by A/B to pump the oil by itself or the Total oil in the reservoir
(1) Pump A by itself would require half the time that Pump B would require.
This statement gives only the rate of A and B. But does not give any info on either the Time taken by A/B to pump the oil alone or the Total oil in the reservoir. This statement is insufficient.
(2) Pump A would require 90 hours by itself to pump the reservoir.
This statement gives the time tken by A to pump the oil by itself. But gives no info on the rate of A and B. Hence this statement is insufficient.
combining both statements we get the necessary information to solve this question.
Answer is C
21 May 2017, 04:28
Kudos
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Bunuel
Two pumps, A and B, are pumping oil out of a reservoir at the same time. If the two pumps are independent of each other, how long would it take to pump all the oil of the reservoir?
(1) Pump A by itself would require half the time that Pump B would require. (to empty the reservoir)
(2) Pump A would require 90 hours by itself to pump the reservoir.
(1) Pump A by itself would require half the time that Pump B would require. (to empty the reservoir)
(2) Pump A would require 90 hours by itself to pump the reservoir.
Total amount in reservoir(A) = (Ra + Rb ) * time taken
Statement 1 : Ra = 2 Rb but total amount is not given. Therefore statement 1 is insufficient .
Statement 2 : Total amount in reservoir(A) = Ra * 90 here we know nothing about Rb . Therefore statement 2 is insufficient .
Combine
A = (A/90 + A/180) * t
A = (A/60) * t
t = 60 hrs
