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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 tank can be filled by a tap in 20 minutes and by another tap in an hour. Both the taps are kept open for 10 minutes and after that the first tap is shutoff. After this, the tank will be totally filled in:
Answer : D
Explanation
Part of the tank filled by both in 10 min. = 10*(1/20+1/60)= 40/60 = 2/3 Remaining part = (1-2/3) = 1/3 1/60 part is now filled in 1 min. 1/3 part is now filled in (60*1/3) min. = 20 min.
Q 3 - Pipes A and B can fill a tank in 20 hours and 30 hours separately and channel C can purge the full tank in 40 hours. In the event that every one of the funnels is opened together, what amount of the reality of the situation will become obvious eventually expected to make the tank full?
Answer : C
Explanation
Net part filled in 1 hr = (1/20+ 1/30 ? 1/40)= 7/120 Time needed to make the tank full = 120/7 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 - 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 substantial tanker can be filled by two pipes A and B in an hour and 40 minutes separately. How long will it take to fill the tanker from unfilled state if B is utilized for a fraction of the time and A and B fill it together for the other half?
Answer : D
Explanation
Let the total time taken be x minute. Then, (1/40*x/2) + (1/60+ 1/40) x/2= 1 ⇒ x/80 + x/48 = 1 ⇒3x+ 5x= 240 ⇒8x= 240 ⇒x= 30 Hence, the required time is 30 minutes.
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 - 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 cistern has two pipes. One can fill it with water in 8 hours and the other can empty it in 5 hours. In how many hours will the cistern be emptied if the both the pipes are opened together when 3/4 of the cistern is already full of water.
Answer : B
Explanation
Part if cistern emptied in 1 hour = 1/5 - 1/8 = 3/40 3/40 part is emptied in hour. ∴ 3/4 part is emptied in 40/3 * 3/4 = 10 hour
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.