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 7 of 9.
Joel said:
4 years ago
Shortcut:
2/75 * 30 + x * 1/45 = 1,
x = 9 min.
2/75 * 30 + x * 1/45 = 1,
x = 9 min.
(38)
Manikant said:
8 years ago
2/75 + 1/45 = 8/225.
How it can be 11/225?
How it can be 11/225?
Vini said:
6 years ago
How will A become 2/75, can anyone explain?
Sudhakar p said:
9 years ago
I can't understand please explain clearly.
Sandhiya said:
8 years ago
Can anyone explain how 2/75 comes? please.
Azharudhin said:
9 years ago
Nice explanation @Mahesh Patil. Thank you.
Vishnupriya said:
1 decade ago
Ya I got it now. Thank you Kasi Srinivas.
Abey said:
6 years ago
Thanks for explaining the answer @Kasi.
Satendra singh said:
9 years ago
(30-X) how came? Please explain me.
Venkatesh said:
1 decade ago
Excellent explanation Kasi Srinivas
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