A pipe can fill a tank in an hour. Because of a leak, it took 1 hour and 10 minutes to fill the tank. Find the time taken by the leak to drain all the water in the tank.
A)
10 minutes
B)
7/6 hours
C)
6/7 hours
D)
7 hours
Correct Option - D
Explanation
Let the leak take x hours to drain the tank.
1 hr 10 min = 1+(1/6) = 7/6 hrs
1-(1/x) = 1/(7/6) = 6/7
Part of tank leaked in an hour = 1-6/7 = 1/7
The leak takes 7 hours to drain all the water.
Pipe A and Pipe B can fill a tank in 1 hour and 1 ¼ hours respectively. Both pipes are opened in the beginning and after some time, pipe B is closed. The tank is filled in 40
A)
30 minutes
B)
45 minutes
C)
40 minutes
D)
25 minutes
Correct Option - D
Explanation
Part of tank filled by A in a minute
= 1/60
Part of tank filled by B in a minute
= 1/75
Let pipe B be closed after x minutes.
Part of tank filled in x minutes
= x*[(1/60)+(1/75)]
= 9x/300
Part of tank filled in (40-x) minutes
= [(40-x)*(1/60)]
= (40-x)/60
(9x/300) + ((40-x)/60) = 1
4x = 100
x = 25
Two taps A and B can fill a bathtub in 10 minutes and 15 minutes respectively. If A was open for the first two minutes, B for the next two minutes and so on, the bathtub is
A)
6 minutes
B)
12 minutes
C)
12.5 minutes
D)
24 minutes
Correct Option - B
Explanation
Part of the tub filled in the first 2 minutes
= 2*1/10 = 1/5
Part of the tub filled in the next 2 minutes
= 2*1/15 = 2/15
Part of the filled in 4 minutes
= (1/5) + (2/15) = 1/3
Time required to fill the tub
= 3*4 = 12 minutes
Two pipes A and B can fill a tank in 20 minutes when opened simultaneously. If pipe A alone takes 60 minutes to fill the tank, how much time will pipe B alone take to fill the
A)
60 minutes
B)
40 minutes
C)
30 minutes
D)
20 minutes
Correct Option - C
Explanation
Let B take x minutes to fill the tank.
Part of the tank filled by A and B
= (1/60) + (1/x) = (1/20)
Solving this, x=30
A tank has three inlets A, B and C. C takes twice the time taken by A to fill the tank and B takes half the time taken by A to fill the tank. If they can fill the tank together in 4
A)
7 minutes
B)
14 minutes
C)
3.5 minutes
D)
28 minutes
Correct Option - A
Explanation
Let A take x minutes to fill the tank.
(1/x) + (1/(x/2)) + (1/2x) = 1/4
(7/2x) = ¼
x = 14
x/2 = 7
An inlet pipe fills a tank at the rate of 5 litres of water a minute. An outlet connected to the tank can empty a full tank in 5 hours. Both the pipes are opened together for 30
A)
480 liters
B)
360 liters
C)
300 liters
D)
240 liters
Correct Option - C
Explanation
Let the inlet pipe take x minutes to fill the tank.
Part of the tank filled by the inlet in a minute
= (1/x)
Part of the tank emptied by the outlet in a minute
= 1/(5*60) = 1/300
Part of the tank filled in the first 30 minutes
= 30*[(1/x)-(1/300)]
= (300-x)/10x
Part of the tank filled in the next 36 minutes
= 36*(1/x)
1 – [(300-x)/10x] = 36/x
Solving, x = 60
Capacity of the tank = 60*5 = 300 liters
Pipe A and Pipe B can fill a tank in 20 minutes and 30 minutes respectively. Pipe C can empty the tank in 60 minutes. The tank is initially empty. Both the pipes A and B are
A)
12 minutes
B)
13.5 minutes
C)
15 mintes
D)
14.5 minutes
Correct Option - B
Explanation
1/20th of the tank is filled by Pipe A in 1 minute.
1/30th of the tank is filled by Pipe B in 1 minute.
1/60th of the tank is emptied by Pipe C in 1 minute.
Part of tank filled in the first 6 minutes = 6*[(1/20)+(1/30)] = 1/2
When all pipes are opened, part of tank filled in 1 minute = (1/12)-(1/60) = 1/15
Time required to fill the remaining ½ of the tank = (1/2)/(1/15) = 7.5
Total time = 6+7.5 = 13.5 minutes