- Aptitude - Home
- Aptitude - Overview
- Quantitative Aptitude
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 - Two funnels can fill a tank in 20 minutes and 30 minutes separately. On the off chance that both the channels are opened at the same time, then the tank will be filled in:
Answer : B
Explanation
Part filled by both pipes in 1 min. =(1/20+ 1/30)= 5/60 = 1/12 Time taken to fill the tank = 12 minutes
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 reservoir has three channels A, B and C. A and B can fill it in 3 hrs and 4 hrs. individually while C can exhaust the totally filled reservoir in 1 hours. On the off chance that the funnels are opened all together at 3 pm, 4 pm and 5 pm individually, at what the truth will surface eventually reservoir void?
Answer : B
Explanation
Let the cistern be emptied in x hrs after 3 pm Work done by A in x hrs, by B in(x-1) hrs and by C in (x-2) hrs= 0 ⇒x/3 +x-1/4 ? (x-2) =0 ⇒ 4x+3(x-1)-12(x-2) = 0 ⇒5x=21 ⇒x= 4 hrs 12 min. Required time is 7.12 pm.
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 - 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.