# Aptitude - Pipes & Cisterns Online Quiz

Following quiz provides Multiple Choice Questions (MCQs) related to **Pipes & Cisterns**. You will have to read all the given answers and click over the correct answer. If you are not sure about the answer then you can check the answer using **Show Answer** button. You can use **Next Quiz** button to check new set of questions in the quiz.

Q 1 - A tap can fill storage in 8 hours and another tap can discharge it in 16 hours. In the event that both the taps are open, the time taken to fill the tank will be:

### Answer : C

### Explanation

Net part filled in 1 hr = (1/8 ? 1/16)= 1/16 Total time taken to fill the tank = 16 hrs.

Q 2 - A pump can fill a tank with water in 2 hours. In light of a break in the tank, it takes 7/3 hours to fill the tank. The hole can discharge the filled tank in:

### Answer : D

### Explanation

Part filled by the pump in 1 hr = 1/2 Net part filled by the pump and leak in 1 hr = 3/7 Emptying work done by the leak in 1 hr= (1/2 - 3/7)= 1/14 Leak can empty the tank in 14 hours.

Q 3 - A storage has two funnels. One can fill it with water in 8hours and the other can exhaust it in 5 hours. In how long will the reservoir be purged if both the channels are opened together when 3/4 of the storage is now loaded with water?

### Answer : C

### Explanation

Net part emptied by both in 1 hr = (1/5-1/8)= 3/40 3/40 part is emptied in 1 hr. 3/4 part will be emptied in (40/3*3/4) hrs = 10 hrs.

Q 4 - Two channels can fill a tank in 15 hours and 12 hours separately and a third pipe can purge it in 4 hours. In the event that the channels are opened all together at 8 am, 9 am and 11am separately, the tank will be exhausted at

### Answer : D

### Explanation

Let the tank be emptied in x hrs after 8 am. Work done by A in x hrs, by B in (x-1) hrs and C in (x-3) hrs = 0 ⇒x/15+ (x-1)/12- (x-3)/4 = 0 ⇒ 4x+5(x-1) - 15(x-3) = 0 ⇒6x= 40 ⇒x= 20/3 hrs. ⇒x= 6 hrs. 40 min after 8 am Hence the tank will be emptied at 14 hrs 40 min, i.e., 2:40 pm

Q 5 - Two pipes A and B can fill a reservoir in 6 minutes and 7 minutes separately. Both the funnels are opened then again for 1 minute each. In what the reality of the situation will become obvious eventually fill the storage?

### Answer : C

### Explanation

Part filled by A in 1st min and B in 2nd min =(1/6+ 1/7 )= 13/42 Part filled by (A+B) working alternately in 6 min. (1/2 * 13/42*6) = 13/14 Remaining part = (1-13/14) = 1/14 It is now A's turn. 1/6 part is filled in 1 min. 1/14 part is filled in (6*1/14) min = 3/7 min. Total time taken = 45/7 min.

Q 6 - A tap can fill a tank in 6 hours. After a large portion of the tank is filled, three more comparable taps are opened. What is the aggregate time taken to fill the tank totally?

### Answer : B

### Explanation

Time taken by the tap to make the tank half full= 3 hrs. Remaining part = 1/2 Part filled by 4 taps in 1 hour= (4*1/6) = 2/3 2/3 part is filled in 1 hour. 1/2 part is filled in (3/2*1/2) hr = 3/4 hr = 45 min. Required time = 3hrs 45 min.

Q 7 - A break in the base of a tank can purge the full tank in 6 hours. A channel funnel fills water at the rate of 4 liters for each moment. At the point when the tank is full, the channel is opened and because of the break, the tank is void in 8 hours. The limit of the tank is

### Answer : B

### Explanation

Part filled in 1 hour = (1/6-1/8)= 1/24 So, the inlet can fill the tank in 24 hours. Capacity of the tank= volume of water that flows in 24 hrs = (4*60*24) ltr. = 5760 liters.

Q 8 - Pipes A and B can fill a tank in 10 hours each. A third pipe C empties the tank in 20 hours. If all the three pipes are opened simultaneously, in how much time will the tank be filled?

### Answer : B

### Explanation

Net part filled in 1 hour = (1/10 + 1/10 - 1/20) = (2+2-1) /20 = 3/20 ∴ Tank will be full in 20/3 = 18/3 hours = 6 hr 40 min

Q 9 - A pump can fill a tank with water in 2 hours. Because of a leak in the tank, it takes 7/3 hours to fill the tank. The leak can empty the filled tank in?

### Answer : D

### Explanation

Part of the tank filled by the pump in 1 hour = 1/2 Part of the tank filled by the pump in 1 hour because of the leak = 3/7 ∴ Part of the tank emptied by the leak in 1 hour = 1/2 - 3/7 = 1/14 ∴ Leak will empty the tank in 14 hours.

Q 10 - Taps A, B and C are connected to a water tank and the rate of flow of water is 42 ltr/hr, 56 ltr/hr and 48 ltr/hr respectively. A and ill fill the tank while tap C empties the tank. If the three taps are opened simultaneously, the tank gets filled up completely in 16 hours. What is the capacity of the tank?

### Answer : A

### Explanation

Net amount of water filled in 1 hr when all the pipes are opened simultaneously = 42 + 56 ? 48 = 50 ltr Tank gets completely filled in 16 hrs. ∴ Capacity of tank = 16*50 = 800 liters.