Pipes and Cistern- Aptitude Questions and Answers

View in English View in Hindi

44 pipes can fill a large water tank in 27 hours. How many hours it take for 66 pipes to fill four such tanks ?

A)
72

B)
54

C)
63

D)
84


Correct Answer :

72


Explanation :

44 pipes => 27 hours
66 pipes=> ?

Amount of work done is same for filling a pipe, So
44*27 = 66*X
X = 44*27 / 66
X = 18
66 pipes can fill one tanks in 18 hours.
they will fill 4 tanks in 18*4 = 72 hours

Post comment
Cancel
Thanks for your comment.!
Write a comment(Click here) ...
View in English View in Hindi

Three pipes A, B and C together can fill a cistern in 6 hours. After working together for 2 hours, C is closed and A and B fill the remaining cistern in 8 hours. Then the time in which the cistern can be filled by pipe C alone will be:

A)
11 hours

B)
9 hours

C)
12 hours

D)
10 hours


Correct Answer :

12 hours


Explanation :

Three Pipes A,B and C together filled a tank in 6 hours
So 1 hour work of A,B and C =1/6
C closed after 2 hour's, Part filled in 2 hours working together(A,B and C) = 2/6 = 1/3
Remaining part = (1-1/3) = 2/3

A and B can fill remaining in 8 hours, (A + B)'s 8 hour's work = 2/3

So, (A+B)'s 1 hour work = 2/24=1/12

Therefore C's 1 hour's work
= [(A+B+C)'s 1 hour]-[(A+B)'s 1 hr work]
=(1/6 - 1/12) = 1/12

C alone can fill the tank in 12 hours

Two pipes A and B can fill a cistern in 4 and 6 minutes respectively. If both the pipes kept turned on alternatively for one minute each starting from A, how long will it take to fill the cistern?

A)
3(3/7) minutes

B)
6 minutes

C)
4(2/3) minutes

D)
6(6/7) minutes


Correct Answer :

4(2/3) minutes


Explanation :

As the pipes are operating alternatively for one minute, thus (A+B)'s 2 minutes job is =(1/4 +1/6) =5/12
in next, 2 minutes both pipe can fill another 5/12 part.
So in 4 minutes A and B are operating alternatively will fill 5/12 + 5/12 = 5/6

Remaining part of cistern= 1 - 5/6 =1/6

Pipe A can fill 1/4 part of the cistern in 1 minute,and can fill 1/6 part of the cistern in = 4*(1/6) =2/3 minutes

Total time taken to fill the Cistern = time taken to fill (5/6 part + 1/6 part)
=> 4 minutes + 2/3 minutes = 4(2/3) minutes Or, 4 minutes 40 seconds

Pipe A can fill a tank in 45 hrs and pipe B can fill it in 36 hrs. If both the pipes are opened in the empty tank. In how many hours will it be full?

A)
10 hr

B)
15 hr

C)
20 hr

D)
28 hr


Correct Answer :

20 hr


Explanation :

If a pipe can fill a tank in x hours, then : part filled in 1 hour = 1/x

Part filled A in 1 hr= (1/45)
Part filled B in 1 hr= (1/36)
Part filled by (A+B) together in 1 hr=(1/45)+(1/36)=1/20

So, The tank will be full in 20 hr.

If a pipe fills a tank in 6 h, then what part of the tank will the pipe fill in 1 h?

A)
1/3

B)
1/6

C)
1/4

D)
1/5


Correct Answer :

1/6


Explanation :

If a pipe can fill a tank in x hours, then : part filled in 1 hour = 1/x

Then,when a pipe fills a tank in 6 h, then the part of tank filled in 1 h = 1/6
Hence ,required part of the tank to be filled in 1h = 1/6 part

A tap can fill a tank in 16 minutes and another can empty it in 8 minutes. If the tank is already half full and both the taps are opened together, the tank will be ?

A)
Filled in 12 min

B)
Emptied in 12 min

C)
Filled in 8 min

D)
Emptied in 8 min


Correct Answer :

Emptied in 8 min.


Explanation :

If a pipe can fill a tank in x hours and another pipe can empty the full tank in y hours (where x > y), then on opening both the pipes, the net part emptied in 1 hour = (1/y)-(1/x)

= (1/8 - 1/16) = 1/16
Time taken to empty the full tank = 16 min.
Hence, time taken to empty the half tank = 8 min

One tap can fill a cistern in 2 hours and another can empty the cistern in 3 hours. How long will they take to fill the cistern if both the taps are opened ?

A)
5 hours

B)
6 hours

C)
7 hours

D)
8 hours


Correct Answer :

6 hours


Explanation :

If a pipe can .fill a tank in x hours and another pipe can empty the full tank in y hours (where y> x), then on opening both the pipes, the net part filled in 1 hour = (1/x)-(1/y)

= (1/2 - 1/3) = 1/6
Hence, time taken to fill the cistern = 6 hours

Latest Updates

Agriculture

Which gas is fixed by Rhizobium bacteria present in the root nodules of a pea plant ?

Chemistry

The formation of sulphurous acid involves ?

The acid present in soft drinks is ?

The cathode of a dry cell is made of ?

The number of atoms present in the molecule of an element is known as its?

Physics

If the angle of incidence formed by a ray of light on a plane mirror is 37°, then the angle of refraction is?

A dynamo converts ?

If the time taken for hearing the echo of a girl's voice after reflection from a cliff is 6 seconds, calculate the distance of the girl from cliff ?

The physical quantity corresponding to the rate of change of displacement is..............?

Work done is said to be zero when an object moves at an angle of ............with respect to the force applied ?

Indian Geography

In terms of area, India is the ........largest country in the world ?

Indian Politics

How many members from the Anglo Indian community are nominated to the Lok Sabha?

Which of the following parts of the Constitution of India provides fundamental rights ?

Time and Work

Ram could complete a job alone in 6 days but Sunil would take thrice the time to do it alone.They started the work together but Ram had to leave a few days before the completion of the work and Sunil had to complete the remaining task by himself. If as a result , it took 6.75 days in all to complete the job, for how many days did the duo work together?

Profit and Loss

The cost price of 20 articles is equal to the selling price of 16 articles. Find the gain or loss percent?

Discount

Successive discount of 10% and 10% are equivalent to a single discount of ?

A discount series of 10%, 20% and 40% is equal to single discount of ?

Pepsi and Coke, there are two companies, selling the packs of cold­drinks. For the same selling price Pepsi gives two successive discounts of 10% and 25% on marked price, while Coke sells it by giving two successive discounts of 15% and 20% on marked price. What is the ratio of their marked price?