Aptitude - Pipes and Cistern - Discussion
Discussion Forum : Pipes and Cistern - General Questions (Q.No. 13)
13.
A tap can fill a tank in 6 hours. After half the tank is filled, three more similar taps are opened. What is the total time taken to fill the tank completely?
Answer: Option
Explanation:
Time taken by one tap to fill half of the tank = 3 hrs.
| Part filled by the four taps in 1 hour = |  |
4 x | 1 |  |
= | 2 | . |
| 6 | 3 |
| Remaining part = | |
1 - | 1 | |
= | 1 | . |
| 2 | 2 |
 |
2 | : | 1 | :: 1 : x |
| 3 | 2 |
 x = |
|
1 | x 1 x | 3 | |
= | 3 | hours i.e., 45 mins. |
| 2 | 2 | 4 |
So, total time taken = 3 hrs. 45 mins.
Discussion:
53 comments Page 2 of 6.
Hemanth said:
2 years ago
We know Rate * Time = Capacity.
Rate = 1/6 ,
Capacity = 1/2.
1/6 * time =1/2
Here time = 3hrs for capacity half.
Next, more three pipes total of 4 pipes.
4 * 1/6 = 2/3.
Rate for 4 pipes is 2/3, Time=?, Capacity = another 1/2,
2/3 * time = 1/2.
Here time = 3/4 = 0.75hrs(0.75*60min).
Total time = 3hrs + 0.75hrs(45 min).
Rate = 1/6 ,
Capacity = 1/2.
1/6 * time =1/2
Here time = 3hrs for capacity half.
Next, more three pipes total of 4 pipes.
4 * 1/6 = 2/3.
Rate for 4 pipes is 2/3, Time=?, Capacity = another 1/2,
2/3 * time = 1/2.
Here time = 3/4 = 0.75hrs(0.75*60min).
Total time = 3hrs + 0.75hrs(45 min).
(9)
Dee said:
1 decade ago
If 1 tap takes 6 hours --> 2 taps takes 6/2=3 (half time as fill faster).
If 2 taps takes 6/2=3 (half time)---4 taps takes 3/2=1.5 (i.e 1:30 min).
1:30 min= 60 min +30 min= 90 min.
90 min (time taken by 4 tapes to fill full tank).
But left is only half tank.
So 90/2 = 45 min.
Now total time = 3hour+45 min.
If 2 taps takes 6/2=3 (half time)---4 taps takes 3/2=1.5 (i.e 1:30 min).
1:30 min= 60 min +30 min= 90 min.
90 min (time taken by 4 tapes to fill full tank).
But left is only half tank.
So 90/2 = 45 min.
Now total time = 3hour+45 min.
JISHNU said:
9 years ago
1 pipe takes 6 hrs to fill the tank.
So 1 pipe take 3 hrs to fill half the tank.
Other half is filled with 4 pipes,
The part of the tank filled with 4 pipes in 1 hr = 4 * 1/6 = 2/3.
So, the time taken to fill half the tank = (1/2) / (2/3)= (1/2) * (3/2) = 3/4 hrs= 45 minutes.
So the total time = 3hrs 45 minutes.
So 1 pipe take 3 hrs to fill half the tank.
Other half is filled with 4 pipes,
The part of the tank filled with 4 pipes in 1 hr = 4 * 1/6 = 2/3.
So, the time taken to fill half the tank = (1/2) / (2/3)= (1/2) * (3/2) = 3/4 hrs= 45 minutes.
So the total time = 3hrs 45 minutes.
Om ouri said:
1 decade ago
1 hour--------->1/6 part of tank.
3 hours--------->1/2 part of tank.
So 1/2 already filled and 1/2 has to be filled.
Now 4 similar taps are opened so total time taken is (1/6+1/6+1/6+1/6) =2/3.
Time to fill remaining 1/2 is 1/2=2/3*x.
X=3/4=.75.
Thus total time taken= 3 +.75 = 3.75.
3 hours--------->1/2 part of tank.
So 1/2 already filled and 1/2 has to be filled.
Now 4 similar taps are opened so total time taken is (1/6+1/6+1/6+1/6) =2/3.
Time to fill remaining 1/2 is 1/2=2/3*x.
X=3/4=.75.
Thus total time taken= 3 +.75 = 3.75.
Doctor said:
1 decade ago
1 tap takes 6 hours.
2 taps will take 3 hours.
Similarly 4 taps will take one and half hour i.e. 90 minutes to completely fill the tank.
Therefore, for half part it will take 45 minutes.
First tap will take 3 hours to half fill the tank.
Hence, we get 3 hours 45 minutes as answer.
2 taps will take 3 hours.
Similarly 4 taps will take one and half hour i.e. 90 minutes to completely fill the tank.
Therefore, for half part it will take 45 minutes.
First tap will take 3 hours to half fill the tank.
Hence, we get 3 hours 45 minutes as answer.
Sarita said:
7 years ago
Hi everyone.
One of the easiest way
Whole tank is filled in 6hour.
Half tank will be filled in 3hour.
But now half tank is remaining and there are a total of 4taps.
So convert 3hour to minutes =180minute.
Now just divide,
180/4 =45 minutes.
So total will be 3hour 45 minutes.
One of the easiest way
Whole tank is filled in 6hour.
Half tank will be filled in 3hour.
But now half tank is remaining and there are a total of 4taps.
So convert 3hour to minutes =180minute.
Now just divide,
180/4 =45 minutes.
So total will be 3hour 45 minutes.
(1)
M.V.KRISHNA said:
1 decade ago
Given A tap can fill a tank in 6 hours.
After half the tank is filled i.e. after 3 hrs.
three more similar taps are opened i.e.
no. of taps to fill remaining half tank = 4 taps
when 1 tap is used = (3 hrs/1 tap)
when 4 taps are used = (3 hrs/4 taps)=45min
total= 3hrs+45min
After half the tank is filled i.e. after 3 hrs.
three more similar taps are opened i.e.
no. of taps to fill remaining half tank = 4 taps
when 1 tap is used = (3 hrs/1 tap)
when 4 taps are used = (3 hrs/4 taps)=45min
total= 3hrs+45min
(1)
Debapriya paul said:
7 years ago
1/6 part filled by one tap in 1 hr.
1/2 part filled by one tap in 3hrs.
Part filled by 4 taps in 1hr is 4 * (1/6)=2/3.
2/3 part filled by 4 taps in 1 hr.
1/2 part filled by 4 taps in 3/4 hr.
So , total time = 3hr + (3/4)hr.
=3 hr 45 mins(answer).
1/2 part filled by one tap in 3hrs.
Part filled by 4 taps in 1hr is 4 * (1/6)=2/3.
2/3 part filled by 4 taps in 1 hr.
1/2 part filled by 4 taps in 3/4 hr.
So , total time = 3hr + (3/4)hr.
=3 hr 45 mins(answer).
(9)
Sankar said:
6 years ago
One tap can fill the whole cistern in = 6 hr,
And half(1/2)tank can fill in = 3 hr.
Remaining (1/2)tank will filled with the 4 pipes(1+3) = 3hr = 180min,
4 pipes = 180/4 = 45min.
So the final answer is (1half+2nd half) = 3hr + 45min,
3hr and 45min.
And half(1/2)tank can fill in = 3 hr.
Remaining (1/2)tank will filled with the 4 pipes(1+3) = 3hr = 180min,
4 pipes = 180/4 = 45min.
So the final answer is (1half+2nd half) = 3hr + 45min,
3hr and 45min.
Nithin said:
9 years ago
Its pretty much a simple logic.
Tone tap 6 hrs to fill.
So 3 hrs to half fill.
A = 1/6.
4 taps 4a =4 * (1/6).
=> 2/3.
Now x be the tank capacity.
X/2 has filled already.
So remaining x/2 in 2/3.
X = 4/3 45 minutes.
So, totally 3 hrs 45 mts.
Tone tap 6 hrs to fill.
So 3 hrs to half fill.
A = 1/6.
4 taps 4a =4 * (1/6).
=> 2/3.
Now x be the tank capacity.
X/2 has filled already.
So remaining x/2 in 2/3.
X = 4/3 45 minutes.
So, totally 3 hrs 45 mts.
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