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?
3 hrs 15 min
3 hrs 45 min
4 hrs
4 hrs 15 min
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.

Aadarsh kumar said:   5 years ago
As we know, rate * time =capacity.

So, after half filled.
A*3=4A *t
t=3/4 hour.
So total time taken is the time taken by A to fill half i.e 3 hr + 3/4 hr = 3 hr 45 minutes.
Thanks.
(3)

Gunjan said:   5 years ago
Thanks @Faysal.
(1)

Faysal said:   6 years ago
Quick one:
1 pipe fills half of the tank=6/=3 hrs.

Remaining half,
1 pipe takes 3 hr.
4 '' '' =3/4 hr= 45 mins.
Total = 3hrs+45mins(Answer)
(2)

Pramod said:   6 years ago
Simple (3hour/1pipe)+(3hour/4pipe).
(First hf tank)+(sec half tank) = 3(3/4) = in hours then = 3(3*60)/4 = 3hr 45min.

Elakkiya said:   6 years ago
Thanks @vicky.

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.

Shreya said:   6 years ago
A tap can fill a tank in 6 hours.

So, 1/2 of the tank is filled in 3 hours.
Now part of the tank filled by 4 same types of taps in 1 hour is (4 x 1/6) = 2/3,
This means 2/3 part is filled by 4 taps in 1 hr,
So 1 part is filled in 3/2 hr,
So 1/2 part is filled in 3/2 x 1/2 = 3/4 hr = 45 min.

Hence total time taken is 3 hr 45 min.
(1)

Mallikarjun Reddy said:   7 years ago
The tap can fill half the tank in 3 hours i.e, in 180 min,
Then 4 taps can fill half the tank in 180/4 = 45 min,
Total: 3 hours 45 min.
(1)

Soumen said:   7 years ago
a, b, c, d = 6 hrs.
a=6 * 1/2 = 3 hrs.
then 3 hrs.= 180 minutes.
180/4 = 45 minutes.
3 hrs. 45 minutes.

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.
(1)


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