Aptitude - Pipes and Cistern - Discussion
Discussion Forum : Pipes and Cistern - General Questions (Q.No. 5)
5.
A tank is filled by three pipes with uniform flow. The first two pipes operating simultaneously fill the tank in the same time during which the tank is filled by the third pipe alone. The second pipe fills the tank 5 hours faster than the first pipe and 4 hours slower than the third pipe. The time required by the first pipe is:
Answer: Option
Explanation:
Suppose, first pipe alone takes x hours to fill the tank .
Then, second and third pipes will take (x -5) and (x - 9) hours respectively to fill the tank.
 |
1 | + | 1 | = | 1 |
| x | (x - 5) | (x - 9) |
 |
x - 5 + x | = | 1 |
| x(x - 5) | (x - 9) |
(2x - 5)(x - 9) = x(x - 5)
x2 - 18x + 45 = 0
(x - 15)(x - 3) = 0
x = 15. [neglecting x = 3]
Discussion:
69 comments Page 7 of 7.
Pranesh kumar said:
2 decades ago
Why you neglect x=3 for what reasons?
(1)
SABYASACHI said:
1 decade ago
How it became (x-5) and (x-9) ?
Ronnie said:
9 years ago
@Lavanya.
Answer is 3 mins.
Answer is 3 mins.
Basavaraj said:
9 years ago
Why 1/x-9 Comes to negative?
(1)
Prasad said:
2 decades ago
How you have taken 9 hours?
Reshma said:
9 years ago
Nice explanation @Tanu.
Anonymous said:
5 years ago
Thanks @Sai Krishna.
Saimanasa said:
6 years ago
Thank you @Manasa.
(2)
Lalitha said:
10 years ago
Why you neglect 3?
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