Aptitude - Pipes and Cistern - Discussion
Discussion Forum : Pipes and Cistern - General Questions (Q.No. 11)
11.
One pipe can fill a tank three times as fast as another pipe. If together the two pipes can fill the tank in 36 minutes, then the slower pipe alone will be able to fill the tank in:
Answer: Option
Explanation:
Let the slower pipe alone fill the tank in x minutes.
| Then, faster pipe will fill it in | x | minutes. |
| 3 |
 |
1 | + | 3 | = | 1 |
| x | x | 36 |
 |
4 | = | 1 |
| x | 36 |
x = 144 min.
Discussion:
67 comments Page 1 of 7.
Pranathi said:
1 decade ago
Why cant we take 3x for faster pipe and x for slower pipe? if I take in that way im getting answer as 9. Is it right or wrong?.
Pri said:
1 decade ago
Please expain this solution more clearly.
Reshma said:
1 decade ago
@Pranathi.
We are discussing about d time. If we take the time taken by slower pipe as x and faster time pipe as 3x. It means that faster pipe takes more time. Which means our assumption is wrong.
We are discussing about d time. If we take the time taken by slower pipe as x and faster time pipe as 3x. It means that faster pipe takes more time. Which means our assumption is wrong.
Karthiga said:
1 decade ago
Why we take 1/x+3/x instead of x + x/3 =36 ?
Miss Mathphobia said:
1 decade ago
Why not x+x/3=36?
It gives me answer as 27...
It gives me answer as 27...
Anusha said:
1 decade ago
its simple ya , one pipe =1/x;
anther pipe =3/x:
=4x36 sec=144.
comment pls.
anther pipe =3/x:
=4x36 sec=144.
comment pls.
Manasa said:
1 decade ago
Thanks RESHMA.
Sonu choudhary said:
1 decade ago
I am still not understand why we take 1/x+3/x=1/36. Please reply.
Vinoth kumar said:
1 decade ago
@sonu:
if A takes x mins
given tat B works thrice as fast as A
i.e, B takes 1/3 of A's time=x/3
we know tat
1/A+1/b=1/36
1/x+1/(x/3)=1/36
1/x+3/x=1/36
4/x=36
x=4*36
x=144
if A takes x mins
given tat B works thrice as fast as A
i.e, B takes 1/3 of A's time=x/3
we know tat
1/A+1/b=1/36
1/x+1/(x/3)=1/36
1/x+3/x=1/36
4/x=36
x=4*36
x=144
Rishab said:
1 decade ago
How do we know that 1/a + 1/b = 1/36 ?
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