Aptitude - Pipes and Cistern - Discussion
Discussion Forum : Pipes and Cistern - General Questions (Q.No. 9)
9.
Two pipes A and B can fill a tank in 20 and 30 minutes respectively. If both the pipes are used together, then how long will it take to fill the tank?
Answer: Option
Explanation:
| Part filled by A in 1 min = | 1 | . |
| 20 |
| Part filled by B in 1 min = | 1 | . |
| 30 |
| Part filled by (A + B) in 1 min = |  |
1 | + | 1 |  |
= | 1 | . |
| 20 | 30 | 12 |
Both pipes can fill the tank in 12 minutes.
Discussion:
15 comments Page 2 of 2.
Myousry said:
9 years ago
Why therefore both pipes can fill the tank in 12 mins?
Prawesh Pradhan said:
9 years ago
By applying formula,
=> x * y/x + y,
=> 20 * 30/20 + 30,
=> 600/50 = 12.
=> x * y/x + y,
=> 20 * 30/20 + 30,
=> 600/50 = 12.
Hawdhaa said:
9 years ago
Thank you for explaining the solution.
Rajesh said:
9 years ago
@Animesh.
(45 + 30) = 75, (45 * 30) = 1350.
75/1350,
= 1/18.
Answer: 1/18.
(45 + 30) = 75, (45 * 30) = 1350.
75/1350,
= 1/18.
Answer: 1/18.
Jamshaid said:
3 years ago
Tank filled in 4 min = 4 * (1/15+1/20) = 28/60,
Remaining = 32/60.
Time for remaining by B = 32/60 / 1/20 = 32*20/60 = 10.2/60.
Remaining = 32/60.
Time for remaining by B = 32/60 / 1/20 = 32*20/60 = 10.2/60.
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