Aptitude - Pipes and Cistern - Discussion
Discussion Forum : Pipes and Cistern - General Questions (Q.No. 12)
12.
A large tanker can be filled by two pipes A and B in 60 minutes and 40 minutes respectively. How many minutes will it take to fill the tanker from empty state if B is used for half the time and A and B fill it together for the other half?
Answer: Option
Explanation:
| Part filled by (A + B) in 1 minute = |  |
1 | + | 1 |  |
= | 1 | . |
| 60 | 40 | 24 |
Suppose the tank is filled in x minutes.
| Then, | x | |
1 | + | 1 | |
= 1 |
| 2 | 24 | 40 |
 |
x | x | 1 | = 1 |
| 2 | 15 |
x = 30 min.
Discussion:
51 comments Page 4 of 6.
Abhishek said:
1 decade ago
@Salini.
I completely agree to your let method and the what question is saying. But through LCM method also answer would be 28 min 48 seconds.
I completely agree to your let method and the what question is saying. But through LCM method also answer would be 28 min 48 seconds.
Mehedi Alam said:
6 years ago
Total = 240 units.
Efficiency of A = 4 unit.
Efficiency of B = 6.
So required time = (240 *1/2) /6+(120/10) = 20+12 = 32.
Why ans is 30?
Efficiency of A = 4 unit.
Efficiency of B = 6.
So required time = (240 *1/2) /6+(120/10) = 20+12 = 32.
Why ans is 30?
(7)
Emon said:
8 years ago
Check the question. It is said half the time. So the answer is 30.
If it is said half of the tanker then the answer would be 32.
If it is said half of the tanker then the answer would be 32.
(1)
Chinmay said:
7 years ago
Question is asked in terms of time, not volume (work). So, 30 mins is the answer. LCM method assumes half volume not half time.
(1)
Anis said:
7 years ago
That means A take halftime but B take full time.
Let's total time t.
So, t/ 2(1/60) + t/ 40=1.
So, t= 30 minutes.
Let's total time t.
So, t/ 2(1/60) + t/ 40=1.
So, t= 30 minutes.
(2)
Leonard said:
1 decade ago
this question is confused me because the real story would not be happen like that. please some one to explain it?
Shreyash said:
9 years ago
When you consider half the volume the answer is 32. But when you consider half the time the answer is 30.
Shubham said:
1 decade ago
But as calculated so both A and B will fill tank in 24min?
So what about this?
So what about this?
Siddhant said:
10 years ago
@Vinayak.
How will you multiply (2*3) you need to add them?
How will you multiply (2*3) you need to add them?
Tom said:
1 decade ago
I don't understand that how 1/40 is for one minutes?
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