# 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 - In 1 minute 3/7 of a basin is filled. Whatever remains of the container can be filled in:

### Answer : B

### Explanation

Part filled in 1 min. = 3/7. remaining part = (1- 3/7)= 4/7 Let the required time be x min. More part, more time taken. (Direct) 3/7: 4/7:: 1: x ⇒ 3x/7 = (4/7*1) ⇒ x= 4/3 min.

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 pipes A and B can fill a tank in 15 minutes and 20 minutes separately. Both the channels are opened together. Be that as it may, following 4 minutes, pipe is turned off. What is the aggregate time required to fill the tank?

### Answer : D

### Explanation

Part filled by both in 4 min. = 4*(1/15+1/20)= (4*7/60)= 7/15 Part unfilled = (1-7/15) = 8/15 1/20 part is filled by B in 1 min. 8/15 part is filled by B in (20*8/15) min. = 32/3 min = 10 min 40 sec. Total time taken = (4 min+10 min 40 sec.) = 14 min 40 sec.

Q 5 - A tank is fitted with two taps A and B. A can fill the tank totally in 45 minutes and B can purge the full tank in 60 minutes. On the off chance that both the taps are opened on the other hand for 1 minute, then in what amount of time the unfilled tank will be filled totally?

### Answer : D

### Explanation

Work done by A in 1st minutes and B 2nd minute= (1/45- 1/60)= 1/180 Part filled in 2 min = 1/180 Part filled in 358 min = (1/360*358) = 358/360 = 179/180 Remaining part = (1-179/180) = 1/180 1/45 part is filled by A in (45*1/180) min= 1/4 min. Total time taken to fill it = 358 1/4 min = 5 hrs.58 min 15 sec.

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 - If two funnels work at the same time, the repository will be filled in 12 hours. One channel fills the store 10 hours quicker than the request. How long does the speedier funnel take to fill the store?

### Answer : C

### Explanation

Suppose that one pipe takes x hours to fill the reservoir. Than the other pipes takes (x-10) hours. ∴ 1/x+ 1/(x-10) = 1/12 ⇒12(x-10+x)= x(x-10) ⇒x^{2}-34x +120=0 ⇒(x-30) (X-4) =0 ⇒x= 30 or x= 4 So, the faster pipe takes 30 hrs to fill the reservoir.

Q 8 - A cistern has 3 pipes A, B and C. A and B can ill it in 3 hours and 4 hours respectively while C can empty the completely filled cistern in 1 hour. If the pipes are opened in order at 3, 4 and 5 pm respectively, at what time will the cistern be empty?

### Answer : A

### Explanation

In 2 hours Pipe A will fill = 2/3 tank In 1 hour Pipe B will fill = 1/4 tank Part of tank filled till 5 PM = (2/3) + (1/4) = 11/12 Remaining part = 1 - (11/12) = 1/12 Net part emptied when A, b and C are opened = (1/3) +( 1/4) - 1 = (4+3-12)/12 = -5/12 ∴ 5/12 part is emptied in 1 hour. ∴ 11/12 is emptied in (12/5)*(11/12) = 11/5 = 2 hr 12 min ∴ Tank will be emptied at 7:12 PM.

Q 9 - Two pipes A and B can fill a water tank in 20 and 24 min respectively. A third pipe C can empty at the rate of 3 gallons per minute. If A, B and C opened together fill the tank in 15 min, the capacity of the tank (in gallons) is:

### Answer : C

### Explanation

Let the capacity of the tank = x gallons Quantity of the water filled in the tank in 1 min when all the pipes A, B and C are opened simultaneously= x/20 + x/24 - 3 According to question, x/20 + x/24 - 3 = x/15 or, x/20 + x/24 - x/15 = 3 or, (6x + 5x - 8x)/120 = 3 or, 3x/120 = 3 or, x = 120 gallons

Q 10 - Two pipes can fill a tank in 12 hours and 15 hours respectively. A third pipe can empty it in 20 hours. If the tank is empty and all the three pipes are opened, then the tank will be full in (in hour) ?

### Answer : C

### Explanation

Part of tank filled by both the pipes in 1 hour = 1/12 + 1/15 = 3/20 Part of tank emptied by third pipe in 1 hour = 1/20 ∴ Part of tank filled when all the pipes are opened simultaneously = 3/20 - 1/20 = 2/20 = 1/10 ∴ Tank will be filled in 10 hours.