Aptitude - Pipes and Cistern - Discussion
Discussion Forum : Pipes and Cistern - General Questions (Q.No. 4)
4.
Two pipes A and B can fill a cistern in 37
minutes and 45 minutes respectively. Both pipes are opened. The cistern will be filled in just half an hour, if the B is turned off after:
minutes and 45 minutes respectively. Both pipes are opened. The cistern will be filled in just half an hour, if the B is turned off after:
Answer: Option
Explanation:
Let B be turned off after x minutes. Then,
Part filled by (A + B) in x min. + Part filled by A in (30 -x) min. = 1.
 x |
 |
2 | + | 1 |  |
+ (30 - x). | 2 | = 1 |
| 75 | 45 | 75 |
 |
11x | + | (60 -2x) | = 1 |
| 225 | 75 |
11x + 180 - 6x = 225.
x = 9.
Discussion:
90 comments Page 8 of 9.
Ashu said:
10 years ago
Why x is multiplied by total work?
Guri said:
3 years ago
Good explanation. Thanks everyone.
(5)
Nins said:
1 decade ago
What is the meaning of "1" here?
Kouser said:
9 years ago
Good explanation @Kasi Srinivas.
Raj said:
1 decade ago
Please tell me how we get 2/75?
Subramanya said:
4 years ago
Well explained, Thanks @Nazmul.
(3)
Rekha said:
4 years ago
Well explained, Thanks @Ashwin.
(2)
Shwetha cr said:
1 decade ago
1 indicates complete cistern.
S.MEENAKSHI said:
1 decade ago
Excellent explanation KASI.
Swapna said:
7 years ago
Thank you @Pintu Francis.
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