Aptitude - Pipes and Cistern - Discussion
Discussion Forum : Pipes and Cistern - General Questions (Q.No. 6)
6.
Two pipes can fill a tank in 20 and 24 minutes respectively and a waste pipe can empty 3 gallons per minute. All the three pipes working together can fill the tank in 15 minutes. The capacity of the tank is:
Answer: Option
Explanation:
| Work done by the waste pipe in 1 minute = | 1 | - |  |
1 | + | 1 |  |
| 15 | 20 | 24 |
| = | |
1 | - | 11 | |
| 15 | 120 |
| = - | 1 | . [-ve sign means emptying] |
| 40 |
 Volume of |
1 | part = 3 gallons. |
| 40 |
Volume of whole = (3 x 40) gallons = 120 gallons.
Discussion:
48 comments Page 2 of 5.
Snhk said:
9 years ago
L.C.M of 20, 15, 24 = 120 unit total capacity.
1st pipe = 6 unit.
2nd pipe = 5 unit.
= 11 unit.
Total 120/15 = 8 unit.
3rd (-) pipe capacity = (11 - 8) = 3 unit.
As UTC 120.
3rd pipe can empty = 120/3 = 40 unit which is = 3 gallons per minute.
Hence the capacity of the tank (40*3) =120 gallons.
1st pipe = 6 unit.
2nd pipe = 5 unit.
= 11 unit.
Total 120/15 = 8 unit.
3rd (-) pipe capacity = (11 - 8) = 3 unit.
As UTC 120.
3rd pipe can empty = 120/3 = 40 unit which is = 3 gallons per minute.
Hence the capacity of the tank (40*3) =120 gallons.
Bagga said:
6 years ago
A=20m, B=24m, Let c=x min.
Now LCM= 120x(Let Capacity of Tank).
Part filled per min:
A = 6x.
B = 5x.
C = 120.
Now given tank filled in 15 min.
therefore, 120x/11x-120 = 15.
solve this x = 40.
Now given C fills 3 Gallon in 1 min which is its efficiency.
Hence 40 * 3 = 120 Capacity of Tank.
Now LCM= 120x(Let Capacity of Tank).
Part filled per min:
A = 6x.
B = 5x.
C = 120.
Now given tank filled in 15 min.
therefore, 120x/11x-120 = 15.
solve this x = 40.
Now given C fills 3 Gallon in 1 min which is its efficiency.
Hence 40 * 3 = 120 Capacity of Tank.
(2)
Lingaraj Behera said:
3 years ago
Let A take 20 min B take 24 and C 3g(g for gallons).
So, the LCM of (20,24,3g) is 120 gallons, so A fills 6g per min, B fills 5 g per min and C -3g per min.
In 1 min the tank fill by 5+6-3 = 8 gallons.
It takes 15 min to fill, so tank capacity is 8*15 = 120 gallons.
So, the LCM of (20,24,3g) is 120 gallons, so A fills 6g per min, B fills 5 g per min and C -3g per min.
In 1 min the tank fill by 5+6-3 = 8 gallons.
It takes 15 min to fill, so tank capacity is 8*15 = 120 gallons.
(29)
Abhi said:
5 years ago
Amount filled by the tank in 1 minute = (1/20)+(1/24),
Assuming x= capacity of the tank,
Amount emptied by the tank in 1 minute = (3/x).
Total amount filled in 1 minute when all 3 pipes are on = (1/15).
So,
(1/20+1/24)-(3/x) = (1/15),
Hence, x = 120 gallons.
Assuming x= capacity of the tank,
Amount emptied by the tank in 1 minute = (3/x).
Total amount filled in 1 minute when all 3 pipes are on = (1/15).
So,
(1/20+1/24)-(3/x) = (1/15),
Hence, x = 120 gallons.
(8)
Nasir said:
9 years ago
Let, the capacity of the tank is x gallon.
3 pipes 1 min can fill up (1 / 20 +1 / 24 - 3),
So, 15 min can fill up, 15 (1 / 20 + 1 / 24 - 3),
We get 15 (1 / 20 + 1 / 24 - 3) equally to x.
We get the calculation of x is 120 gallons.
3 pipes 1 min can fill up (1 / 20 +1 / 24 - 3),
So, 15 min can fill up, 15 (1 / 20 + 1 / 24 - 3),
We get 15 (1 / 20 + 1 / 24 - 3) equally to x.
We get the calculation of x is 120 gallons.
(1)
Rabi said:
1 decade ago
Let the capacity of tank x gallons. then in 1 minute tank filled (x/20+x/24-3)gallons
From the question we can write
15(x/20+x/24-3)=x [it took 15 min to fill x gallons]
x/20+x/24-x/15=3
(6x+5x-8x)/120=3
3x/120=3
x=120 gallons
From the question we can write
15(x/20+x/24-3)=x [it took 15 min to fill x gallons]
x/20+x/24-x/15=3
(6x+5x-8x)/120=3
3x/120=3
x=120 gallons
Jamshaid said:
3 years ago
Not agreed.
The Suggested Solution is;
Let Tank be of X Gallons.
Speed of filling X/20+X/24; Emptying in 15 Min = 15 * 3 Gal/Mon = 45 G, then;
15 min filling eq. 15 * (X/20 + X/24) - 45 = X.
X = 25 (15/21) G.
The Suggested Solution is;
Let Tank be of X Gallons.
Speed of filling X/20+X/24; Emptying in 15 Min = 15 * 3 Gal/Mon = 45 G, then;
15 min filling eq. 15 * (X/20 + X/24) - 45 = X.
X = 25 (15/21) G.
(2)
Sreeram said:
9 years ago
A and B.
Time: 20min and 24min.
Efficiency: 6 and 5.
Work done A+B in 1 min = 11.
Work done A+B in 15 min = 11*15 = 165.
Tank emptied by C in 15 min = 45.
= 165 - 45 = 120 gallons.
Time: 20min and 24min.
Efficiency: 6 and 5.
Work done A+B in 1 min = 11.
Work done A+B in 15 min = 11*15 = 165.
Tank emptied by C in 15 min = 45.
= 165 - 45 = 120 gallons.
Shankarbalaji said:
1 decade ago
2 pipes can fill a tank in X and Y times respectively. How to calculate the time taken to fill the tank if both the pipes a open together?
Karan Ratnaparkhi said:
1 decade ago
As per the given condition we have 1/20 + 1/24 + 1/3 = 1/15. Here 1/3 refers to waste pipe nd 1/20, 1/24 refer to other 2 pipes.
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