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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 - 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 channels can fill a tank in x hours and another funnel can exhaust it in y (y>x) hours. In the event that both the funnels are open, in how long will the tank be filled?
Answer : D
Explanation
Work done by filling pipe in 1 hr = 1/x Work done by emptying pipe in 1 hr = 1/y Net filling work done by both in 1 hr = (1/x- 1/y) = (y-x)/xy ∴The tank will be filled in xy/(y-x) hrs.
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 - 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 and B can fill a bucket in 12 min and 15 min respectively. If both the taps are opened and tap A is closed after 3 mins, how much further time would it take for tap B to fill the bucket?
Answer : B
Explanation
Part of bucket filled by tap A and B together in 1 min = 1/12 + 1/15 = 3/20 ∴ Part of bucket filled by A and B in 3 min = 3*3/20 = 9/20 Remaining part = 1 - 9/20 = 11/20 Tap B can fill 11/20 part in 15*11/20 = 33/4 min = 8 min 15 sec