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.
Pranav Kumar said:
10 years ago
I didn't understand the problem could you explain once.
Suman chabri said:
10 years ago
Thanks now I am understood.
Prakash said:
1 decade ago
Let A be faster pipe & B be slower pipe.
We know that [b] Capacity = Work/Time [/b].
Assume the capacity of A as 3 unit/min (i.e. A pipe can fill three times more capacity than B as given in the question).
Then the capacity of B is 1 unit/min.
Total capacity (A+B) = 3+1= 4 unit/min.
If the pipes together (A+B) fill the tank in 36 min, then net work = capacity*time.
i.e Net work = 4*36 = 144 units.
Now the time taken by slower pipe B = Network/Capacity of B.
Time (B) = 144/1 = 144 min.
Similarly for A pipe = 144/3 = 48 min.
Ans: 144 min.
We know that [b] Capacity = Work/Time [/b].
Assume the capacity of A as 3 unit/min (i.e. A pipe can fill three times more capacity than B as given in the question).
Then the capacity of B is 1 unit/min.
Total capacity (A+B) = 3+1= 4 unit/min.
If the pipes together (A+B) fill the tank in 36 min, then net work = capacity*time.
i.e Net work = 4*36 = 144 units.
Now the time taken by slower pipe B = Network/Capacity of B.
Time (B) = 144/1 = 144 min.
Similarly for A pipe = 144/3 = 48 min.
Ans: 144 min.
Hafee said:
1 decade ago
Let it be 3x, 1x.
So, 4x = 1/36.
Then x = 144.
So, 4x = 1/36.
Then x = 144.
PRATYUSH MISHRA said:
1 decade ago
Any one tell me simplest way to solve this question?
Vik said:
1 decade ago
Work done by A in 1 min + Work done by B in 1 min = Work done by both in 1 min.
Madhu reddy said:
1 decade ago
Let's 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.
(1)
L.vignesh said:
1 decade ago
Above answer is right 144 mins.
How when the tank was empty by one slow pipe (B) & 3 times faster pipe then slow its called pipe (A).
Know imagine the tank contain 4 liters of water and time taken to empty is 36 min.
As per above condition the B pipe can take 1 liter of water is 36 min mean the A pipe will take 3 liters at the time (3 times more than B. So 3x1=3).
If the pipe A as been removed the work as gone for B. But the B is 3 times slower.
Now A pipe as take 36 min for 3 liter means B will take 3 times more time 108 min (36x3=108).
Already the pipe B was have taken 36 min (for 1 liter) and adding the 108 min for balance 3 liter after adding the answer was 144 min.
(or).
For 1 liter it take 36 min means for 4 liter its 144 min as per above calculation.
How when the tank was empty by one slow pipe (B) & 3 times faster pipe then slow its called pipe (A).
Know imagine the tank contain 4 liters of water and time taken to empty is 36 min.
As per above condition the B pipe can take 1 liter of water is 36 min mean the A pipe will take 3 liters at the time (3 times more than B. So 3x1=3).
If the pipe A as been removed the work as gone for B. But the B is 3 times slower.
Now A pipe as take 36 min for 3 liter means B will take 3 times more time 108 min (36x3=108).
Already the pipe B was have taken 36 min (for 1 liter) and adding the 108 min for balance 3 liter after adding the answer was 144 min.
(or).
For 1 liter it take 36 min means for 4 liter its 144 min as per above calculation.
Sameer sharma said:
1 decade ago
If a is times faster then b and takes less minutes then in how many time they will fill tank.
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