Quantitative Aptitude Notes Part 11( Pipes and Cisterns)

Pipes and Cisterns

What is Inlet?
Inlet: A Pipe is connected with tank and it fills with water or some liquid is called as Inlet.

What is Outlet?
Outlet: A Pipe connected with tank it emptying is called as an outlet.

 

Remembering points of pipe examples:

  • If a pipe can fill a tank in x hours, then, part filled by 1 hours = .
  • If a pipe can empty a tank in y hours, then, part emptied in 1 hours =
  • 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 hours = ( – ).
  • 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 emptied in 1 hours = ( – ).

 

Example:
Two pipes A and B can fill a tank in 12 hours and 14 hours respectively while a third pipe C empties the full tank in 30 hours.If all the A, B, C operate simultaneously, How much time will take be filled the tank?

Answer:
Step 1: Net part filled by 1 hour = ( + ) – = .
Step 2: The Time taken will fill the tank is  = 8 hr 12 minutes.
So time taken to fill the tank 8 hr 12 minutes.

 

Example:
Two pipes A and B can fill a tank in 36 hours and 45 hours respectively. If both the pipes are simultaneously, how much time will be taken to fill the tank?

Answer:
Here both pipes are working like a inlet,
Step 1: So at first of we calculate fill pipe in 1 hours time taken.
A + B together filled a tank in 1 hour = ( + ) = =

Step 2: So in 1 hour it fill with 1 / 20.
Hence time taken both the pipe A and B will fill the tank in 20 hours.

 

Example:
If A pipe can fill a tank in 12 hr. and pipes B can empty a tank in 20 hr. When both pipes are opened simultaneously, How much time will be taken to fill the tank?
Answer:
Step 1: At we calculate time taken to fill in hour hr and time taken to empty the a tank in  hr.
Step 2: When both pipes are opened then time taken to fill
– = 5 –
=
So in 1 hour to take fill tank both are open A and B =
time taken when A and B are opened, A + B = = 30hr.

 

Example:
Pipes X fill the tank in 6 hours , Pipes Y fill the tank in 10 hours , Pipes Z fill the tank in 20 hours , If all the Pipes are open , in how many hours will the tank be filled ?
Answer:
Part filled by ( X + Y + Z ) in 1 hour  = ( + + ) = .
So that All the three pipes together will fill the tank in 60 / 19hours.

 

 

Example:
There are two types Pipes, Pipes A and B can fill a tank in 3 and 6 hours respectively. Pipe C can empty it in 12 hours. If all the three pipes are opened together, then the tank will be filled in:
Answer: 
Net part filled in 1 hour = (  + – ) = .
The tank will be full in  hrs.

 

Click here to Join Test Series for SSC CGL 2017 by SSCtube (Use Coupon code 'sscnaukari' and get 10% off)

Leave a Reply

Your email address will not be published.