# Aptitude Questions – Pipes & Cistern Set 12

Hello Aspirants. Welcome to Online Quantitative Aptitude Section with explanation in AffairsCloud.com. Here we are creating question sample in Pipes & Cistern which is common for all competitive exams. We have included Some questions that are repeatedly asked in bank exams !!!

1. A Tank is filled with the mixture of Milk and Water in the ratio of 3:2 up to 2/5 of its capacity. The tank has two inlet pipes i.e., Milk and Water inlets. Milk and Water pipe can fill an empty tank in 12 and 18 hours respectively. Now both pipes are opened simultaneously and closed after the Tank is completely filled, then what is the ratio of Milk and Water in the full Tank if it can accommodate 250Litre?
A. 1:1
B. 2:3
C. 3:2
D. 5:4
E. None
Explanation :
Initial Milk = 2/5*250*3/5 = 60 L
Water = 2/5*250*2/5 = 40 L
Rest of Tank =150 L
Pipes are opened then can fill rest of tank in 108/25 hours
H/W = constant
then (108/25)/12/x = (108/25)/18(150-x)
X = 90 = Milk, Water = 60
Final ratio = 3:2

2. An Inlet pipe can fill a tank in 5 hours and an Outlet pipe can empty 4/7 of the same Tank in 4 hours. In the first hour only Inlet pipe is opened and in the second hour, only outlet pipe is opened. They have opened alternately every hour until the Tank is filled. Then in how many hours does the Tank gets filled?
A. 17 Hours 17 Min
B. 34 Hours 60/7 Min
C. 35 Hours 15 Min
D. 36 Hours 60/7 Min
E. None
Answer – B. 34 Hours 60/7 Min
Explanation :
2 hours work = 1/5-1/7 = 2/35
34 hours work = 34/35
remaining work = 1/35
Now its inlet pipe turn = 1/35*5 = 1/7
= 34 hours + 60/7 min

3. A Tank is already filled up to X% of its capacity. An Inlet pipe can fill Full Tank in 30 minutes and an Outlet pipe can empty Full Tank in 20 Minutes. Now both pipes are opened then the Tank is emptied in 24 Minutes. Then initially up to what % of its capacity is Tank filled?
A. 40%
B. 48%
C. 50%
D. 60%
E. Cannot be determined
Explanation :
1/30 – 1/20 = -1/60
Full Tank can be emptied 60 Minutes
In 24 minutes 40% of Tank can be emptied.

4. Two Inlet Pipes A and B together can fill a Tank in ‘X’ minutes. If A and B take 81 minutes and 49 minutes more than ‘X’ minutes respectively, to fill the Tank. Then They can fill the 5/7 of that Tank in how many minutes?
A. 45 Minutes
B. 49 Minutes
C. 63 Minutes
D. 81 Minutes
E. None
Explanation :
Time taken by two pipes to fill full Tank is = √ab min = 63 min
5/7 Tank = 63*5/7 = 45 min

5. Pipe A can fill a Tank in 18 Hours, Pipe B can empty a Tank in 12 Hours, Pipe C can fill Tank in 6 Hours. The Tank is already filled up to 1/6 of its capacity. Now Pipe A is opened in the First Hour alone, Pipe B is opened in the Second Hour alone and Pipe C is opened in the Third Hour alone. This cycle is repeated until the Tank gets filled. Then in How many Hours does the rest of Tank gets filled?
A. 15 Hours
B. 18 Hours
C. 20 Hours
D. 24 Hours
E. None
Explanation :
In First Hour Tank filled = 1/6+1/18
Second Hour = 1/6+1/18-1/12
Third Hour = 1/6+1/18-1/12+1/6 = 11/36 is filled
25/36 is left
From then 3 hours work = 1/18-1/12+1/6 = 5/36
5*3 Hours = 5*5/36 = 25/36
Total = 5*3+3 = 18 Hours

6. If the ratio of Rate of filling of two Pipes A and B is 3:2. If together they can fill a Tank 5/6th of Tank in 20 minutes. Then in how many does A alone can fill the Tank?
A. 20 Minutes
B. 30 Minutes
C. 40 Minutes
D. 50 Minutes
E. 60 Minutes
Explanation :
5/6 tank = 20 Min
Full tank = 24 Min
1/2x+ 1/3x = 1/24
x = 20, A= 2x = 40 Min

7. Pipe A, B and can fill a Full Tank in 24,36 and 48 Minutes respectively. All three Pipes are Opened simultaneously in a Tank which is already filled up to 1/6 of its capacity. A and B are opened for only First 6 Minutes and closed thereafter.Then C alone filled remaining Tank. Then in total how many Minutes does C filled the Tank?
A. 12 Minutes
B. 14 Minutes
C. 16 Minutes
D. 18 Minutes
E. 20 Minutes
Explanation :
6*(1/24+1/36+1/48) + x/48 = 5/6
x = 14 Min
C = 6+14 = 20

8. Pipe A and B can fill a Tank alone in 12 Hours and 6 Hours respectively. Another Pipe C can empty the same Tank alone in 9 Hours. In an empty Tank for the First hour, Pipe A is opened alone, Second Hour pipe B is opened alone, Third Hour pipe C is opened alone. This process is continued until the Tank is filled. Then Pipe A is opened for How many Hours?
A. 7 Hours
B. 7 Hours 10 Min
C. 7 Hours 15 Min
D. 7 Hours 20 Min
E. None
Answer – D. 7 Hours 20 Min
Explanation :
3 hours work = 1/12+ 1/6 – 1/9 = 5/36
7*3 hours work = 35/36
remaining work = 1/36
Now its pipe A turn = 1/36*12 = 1/3 hour
Total = 7 hours + 20 min

9. Pipe A and B can fill a Tank alone in 48 Hours and 24 Hours respectively. Another Pipe C can empty the same Tank alone in 36 Hours. In an empty Tank for the First hour, Pipe A is opened alone, Second Hour pipe B is opened alone, Third Hour pipe C is opened alone. This process is continued until the Tank is filled. Then Pipe B is opened for How many Hours?
A. 28 Hours
B. 28 Hours 10 Min
C. 29 Hours
D. 29 Hours 10 Min
E. None
Answer – B. 28 Hours 10 Min
Explanation :
3 Hours work = (1/48+1/24-1/36) = 5/144
28* 3hours = 140/144
remaining part = 4/144 = 1/36
Now it’s A turn = 1/36-1/48
= 1/144 left
Now it’s B turn = 1/144*24 = 1/6 hour = 10 min
Total B = 28 Hours + 10 Min

10. Two Pipes A and B together can fill a Tank in ‘X’ minutes. If ‘A’ is Inlet Pipe can Fill the Tank alone in 40 minutes less than ‘X’ minutes and ‘B’ is Outlet pipe can empty the Tank alone in 30 minutes less than ‘X’ minutes. Then together they can fill the empty Tank in how many minutes?
A. 48 Minutes
B. 54 Minutes
C. 60 Minutes
D. 70 Minutes
E. None