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 3 of 7.
Prashi said:
10 years ago
Assume A = Fast pipe.
B = Slow pipe.
A takes x time. And B takes 3x time.
So, in 1 min 1/x + 1/3x = 1/36.
By solving 4x/3x^2 = 1/36.
Finally x = 4*36/3.
x = 48.
Time taken by slow pipe = 3x = 3*48 = 144 min.
B = Slow pipe.
A takes x time. And B takes 3x time.
So, in 1 min 1/x + 1/3x = 1/36.
By solving 4x/3x^2 = 1/36.
Finally x = 4*36/3.
x = 48.
Time taken by slow pipe = 3x = 3*48 = 144 min.
Xavier said:
2 years ago
Faster x min slower 3x min eff 3:1 total work LCM of x, 3x is 3x ,
Slower+ faster together = 3x/4.
Given slower + faster together can fill in = 36.
=> 3x/4 = 36.
=> x= 144/3.
Slower pipe =3x =3*144/3= 144.
Slower+ faster together = 3x/4.
Given slower + faster together can fill in = 36.
=> 3x/4 = 36.
=> x= 144/3.
Slower pipe =3x =3*144/3= 144.
(6)
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.
CHANDRA MOHAN NAGAR said:
5 years ago
Work inversely proportional to time.
Fast pipe time = x.
Slow pipe time = 3x (according to question).
Together time = 36min.
1/36 = 1/x + 1/3x.
36*4 = 3x.
3x time take by slow pipe = 144 Answer.
Fast pipe time = x.
Slow pipe time = 3x (according to question).
Together time = 36min.
1/36 = 1/x + 1/3x.
36*4 = 3x.
3x time take by slow pipe = 144 Answer.
(1)
Ssrao said:
5 years ago
Sslower pipe = 3x
Faster pipe = x
1/x + 1/3x = 1/36
(3+1)/3x = 1/36
1/x = 1/27.
Then,
Faster pipe takes 27 mins.
Slower pipe takes 27*3 = 81 mins.
Why this is wrong? Explain.
Faster pipe = x
1/x + 1/3x = 1/36
(3+1)/3x = 1/36
1/x = 1/27.
Then,
Faster pipe takes 27 mins.
Slower pipe takes 27*3 = 81 mins.
Why this is wrong? Explain.
(5)
Saurav said:
1 decade ago
If i take A =x and B=3x then I am getting 27 min as answer is it wrong?
If I assume x as time then A = 9 and B =27 after calculating x+3x=36 is it wrong? please explain.
If I assume x as time then A = 9 and B =27 after calculating x+3x=36 is it wrong? please explain.
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
YOGI M said:
9 years ago
P1 = 3P2 According to the question.
[P1 + P2] = 1/36.
[P2] = ?
P1 + P2 = 1/36.
3P2 + P2 = 1/36.
4P2 = 1/36.
P2 = 1/144 {1/36 * 4 = 144}.
==>P2 = 144min.
[P1 + P2] = 1/36.
[P2] = ?
P1 + P2 = 1/36.
3P2 + P2 = 1/36.
4P2 = 1/36.
P2 = 1/144 {1/36 * 4 = 144}.
==>P2 = 144min.
(1)
Laxman said:
1 decade ago
The simplest way is.
Together the two pipes can fill in 36 min.
That means the fastest one can fill 36*3=108.
And the slowest one is =108+36=144.
Together the two pipes can fill in 36 min.
That means the fastest one can fill 36*3=108.
And the slowest one is =108+36=144.
Yasin said:
1 decade ago
I AM TRYING LIKE THIS but not getting.
First pipe x to fill tank then second one is 3x.
now both 1/x+1/3x=36
4/3x=36
1/x=9???
What's the problem?
First pipe x to fill tank then second one is 3x.
now both 1/x+1/3x=36
4/3x=36
1/x=9???
What's the problem?
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