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:
54 comments Page 6 of 6.
Tushar Pawar said:
3 years ago
They asked total time, so half tank is filled in 3 hour and later it takes 45 min as we calculated. Therefore 3 hour and 45 min.
(3)
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)
Sapna Singh Lodhi said:
9 months ago
The half tank filled in 3 hours since the full took 6 hours.
So, the rest half will be filled by 4 tap = 3 * 60/4 = 45.
Complete time to fill the tank = 3 hours 45 min.
So, the rest half will be filled by 4 tap = 3 * 60/4 = 45.
Complete time to fill the tank = 3 hours 45 min.
(2)
Aditi chaudhary said:
2 weeks ago
Time taken by one tap to fill half of the tank = 3 hours.
Part filled by one tap in 1 hour = 1/6,
Part filled by 4 taps together in 1 hour = 4 × 1/6 = 2/3.
Total part filled by one tap + total part filled by 4 taps = 1.
(3)×(1/6) + (x)×(2/3) = 1.
[where x is the time taken by 4 taps to fill the tank].
Solving the equation we get, x = 3/4.
Now,
The Total time taken to fill the tank = 3 hours + 3/4 hours = 15/4 hours, which can also be written as 3(3/4) hours, which is 3 hours 45 minutes.
So, the correct option is (b) 3 hours 45 minutes.
Part filled by one tap in 1 hour = 1/6,
Part filled by 4 taps together in 1 hour = 4 × 1/6 = 2/3.
Total part filled by one tap + total part filled by 4 taps = 1.
(3)×(1/6) + (x)×(2/3) = 1.
[where x is the time taken by 4 taps to fill the tank].
Solving the equation we get, x = 3/4.
Now,
The Total time taken to fill the tank = 3 hours + 3/4 hours = 15/4 hours, which can also be written as 3(3/4) hours, which is 3 hours 45 minutes.
So, the correct option is (b) 3 hours 45 minutes.
Post your comments here:
Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers