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 6 of 9.
Mahesh Patil said:
1 decade ago
Shortcut
(75/2)-30
----------- * 45 = 9 ....after solving
(75/2)
(75/2)-30
----------- * 45 = 9 ....after solving
(75/2)
Nags said:
1 decade ago
In (2/75)30+(1/45)x = 1.
Where how 30 will come?
I can't understand.
Where how 30 will come?
I can't understand.
Hithma said:
7 years ago
I Can't understand this. Please, someone explain to me. clearly.
Ranjit said:
9 years ago
@Arshad 1605.
How the answer 9 came after the step 105/11?
How the answer 9 came after the step 105/11?
Tapz patel said:
8 years ago
A*(A'work)+B*(B'work)=1,
It means 30(A)+x(B)=1,
Then, x=9.
It means 30(A)+x(B)=1,
Then, x=9.
Priya said:
1 decade ago
Sorry I didn't understood. Please explain me in detail.
Jothigonzi said:
5 years ago
@Abhijeet pol.
Nice and easiest explanation. Thanks.
Nice and easiest explanation. Thanks.
Neha sharma said:
1 decade ago
@Mahesh Patil.
What's the logic behind the short cut?
What's the logic behind the short cut?
Kumar said:
9 years ago
@Arshad1605, Please tell me how 9 came after 105/11?
Vishnupriya said:
1 decade ago
I can't understand still. Can any one say in detail.
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