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 funnel can discharge a tank in 40 minutes. A second pipe with distance across twice as much as that of the first is likewise joined with the tank to purge it. The two together can exhaust the tank in:
Answer : B
Explanation
A pipe with double diameter will take half time. So, the second pipe can empty the full tank in 20 min. Part emptied by both in 1 min. (1/40+ 1/20) = 3/40 Time taken to empty the full tank = 40/3 min.
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 - 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 - Three funnels A, B; C can fill a tank in 6 hours. In the wake of working at it together for 2 hours, C is shut and A and B can fill the remaining part in 7 hours. The quantity of hours taken by C alone to fill the tank is:
Answer : C
Explanation
Part filled by (A+B+c) in 2 hours= (1/6*2)=1/3 2/3 part is filled by (A+B) in 7 hours. Whole is filled by (A+B) in (7*3/2) hr=21/2hrs. Part filled by C in 1 hour = (1/6-2/21) = 3/42 = 1/14 ∴C alone can fill it in 14 hours.
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) ⇒x2-34x +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 - 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 - One pipe can fill a tank three times as fast as another pipe. If together the two pipes can fill the tank in 36 minutes, the slower pipe alone will be able to fill the tank in ?
Answer : D
Explanation
Let the time taken by faster pipe be x min ∴ 1/x + 1/3x = 1/36 Or, (3 +1)/3x = 1/36 Or, x = 48 min ∴ Time taken by slower pipe to fill the tank = 3*48min = 144 min
