Pipes And Cistern(Quantitative Aptitude ) Questions and answers for exam Preparation

Quantitative Aptitude

PIPES AND CISTERN MCQs

Pipes & Cisterns

Total Questions : 431 | Page 9 of 44 pages

Question 81. A tap can completely fill a water tank in 8 hours. The water tank has a hole in it through which the water leaks out. The leakage will cause the full water tank to get empty in 12 hours. How much time will it take for the tap the the tank completely with the hole?

16 hours
18 hours
24 hours
None of these

Discuss Question

Answer: Option C. -> 24 hours

Question 82. A tank can be filled by pipe A in 2 hours and pipe B in 6 hours. At 10 A.M. pipe A was opened. At what time will the tank be filled if pipe B is opened at 11 A.M. ?

12.45 A.M.
5 P.M.
11.45 A.M.
12 P.M.

Discuss Question

Answer: Option C. -> 11.45 A.M.

Question 83. A water tank can be filled by a tap in 30 minutes and another tap can fill it in 60 minutes. If both taps are kept open for 5 minutes and then the first tap is closed, how long will it take foe the tank to be filled ?

20 minutes
25 minutes
30 minutes
45 minutes

Discuss Question

Answer: Option D. -> 45 minutes

Question 84. A pipe can fill a tank in x hours and another can empty it in y hours. In how many hours they together fill it in ( y > x) ?

(x - y) hours
(y - x) hours
$$\left( {\frac{{xy}}{{x - y}}} \right)\,{\text{hours}}$$
$$\left( {\frac{{xy}}{{y - x}}} \right){\text{hours}}$$

Discuss Question

Answer: Option D. -> $$\left( {\frac{{xy}}{{y - x}}} \right){\text{hours}}$$

Question 85. A water tap fills a tub in 'p' hours and a sink at the bottom empties it in 'q' hours. If p < q and both tap and sink are opened the tank is filled in 'r' hours, then the relation between p, q, r :

$$\frac{1}{r} = \frac{1}{p} + \frac{1}{q}$$
$$\frac{1}{r} = \frac{1}{p} - \frac{1}{q}$$
$$r{\text{ = }}p{\text{ }} + {\text{ }}q$$
$${\text{ }}r{\text{ }} = {\text{ }}p{\text{ }} - {\text{ }}q$$

Discuss Question

Answer: Option B. -> $$\frac{1}{r} = \frac{1}{p} - \frac{1}{q}$$

Question 86. Three taps A, B, C can fill an overhead tank in 4, 6 and 12 hours respectively. How long would the three taps take to fill the tank if all of them are opened together ?

2 hours
4 hours
3 hours
5 hours

Discuss Question

Answer: Option A. -> 2 hours

Question 87. Having the same capacity 9 taps fill up a water tank in 20 minutes. How many taps of the same capacity are required to fill up the same water tank in 15 minutes ?

10 taps
12 taps
15 taps
18 taps

Discuss Question

Answer: Option B. -> 12 taps

Question 88. Pipe A can fill a tank in 4 hours and pipe B can fill it 6 hours. If they are opened on alternate hours and if pipe A is opened first then in how many hours, the tank shall be full ?

$${\text{4}}\frac{1}{2}$$ hours
$${\text{4}}\frac{2}{3}$$ hours
$${\text{3}}\frac{1}{2}$$ hours
$${\text{3}}\frac{1}{4}$$ hours

Discuss Question

Answer: Option B. -> $${\text{4}}\frac{2}{3}$$ hours

Question 89. Pipe A can fill the tank in 8 hours and pipe B can fill it in 12 hours. If pipe A is opened at 7:00 AM and pipe B is opened at 9:00 AM, then at what time will the tank be full ?

12:00 PM
12:30 PM
11:48 PM
12:36 PM

Discuss Question

Answer: Option D. -> 12:36 PM

Question 90. Two pipes A and B can fill a tank with water in 30 minutes and 45 minutes respectively. The third pipe C can empty the tank in 36 minutes. First A and B are opened. After 12 minutes C is opened. Total time ( in minutes ) in which the tank will be filled up is -