**Quantitative Aptitude Study Notes for Bank & SSC**

Exam

Exam

**PIPES AND CISTERNS**

You know that quantitative

aptitude section is most important in

other competitive exams because if you want good score in bank exam then you

have to score good in maths. In competitive exams the most important thing is

time management, if you know how to manage your time then you can do well in

tricks and formula are comes into action. So continuously we are providing

shortcut tricks on different maths topics.

aptitude section is most important in

**bank**

exams in PO andexams in PO and

**Clerk**and forother competitive exams because if you want good score in bank exam then you

have to score good in maths. In competitive exams the most important thing is

time management, if you know how to manage your time then you can do well in

**Bank Exams.**That’s where maths shortcuttricks and formula are comes into action. So continuously we are providing

shortcut tricks on different maths topics.

Today’s topic is

topic in quantitative aptitude section in bank and ssc exam. You should know how

to calculate pipe and cisterns questions and answers in very short time for

bank exam. From this chapter around 1-2 questions are given in the

are providing shortcut tricks and

**PIPES AND CISTERNS.**This is the one of the most importanttopic in quantitative aptitude section in bank and ssc exam. You should know how

to calculate pipe and cisterns questions and answers in very short time for

bank exam. From this chapter around 1-2 questions are given in the

**SBI and IBPS exams.**For this here weare providing shortcut tricks and

**quicker**

methodto calculatemethod

**pipe and**

cisternsin very short time.cisterns

Pipes and Cisterns problems are

almost the same as those of Time and Work problems. Thus, if a pipe fills a

tank in 6 hrs, then the pipe fills 1/6 th of the tank in 1 hour. The only

difference with pipes and Cisterns problems is that there are outlets as well

as inlets. Thus, there are agents (the outlets) which perform negative work

too. The rest of the process is almost similar.

almost the same as those of Time and Work problems. Thus, if a pipe fills a

tank in 6 hrs, then the pipe fills 1/6 th of the tank in 1 hour. The only

difference with pipes and Cisterns problems is that there are outlets as well

as inlets. Thus, there are agents (the outlets) which perform negative work

too. The rest of the process is almost similar.

**Inlet:**A pipe connected with a tank (or

a cistern or a reservoir) is called an inlet, if it fills it.

**Outlet:**A pipe connected with a tank is

called an outlet, if it empties it.

**DIRECT FORMULAE AND TIPS FOR PIPES AND CISTERNS QUESTIONS:**

If we want to solve pipe and

cisterns questions or any other type of questions, then the first thing that we

need that is Formulas about that topic. So here is the list of formulas that is

used in time and distance quantitative topic.

cisterns questions or any other type of questions, then the first thing that we

need that is Formulas about that topic. So here is the list of formulas that is

used in time and distance quantitative topic.

i.

If a pipe can fill a tank in x hours, then the part filled in 1

hour = 1/x.

ii.

If a pipe can empty a tank in y hours, then the part of the full

tank emptied in 1 hour = 1/y.

iii.

If a pipe can fill a tank in x hours and another pipe can empty

the full tank in y hours, then the net part filled in 1 hour, when both the

pipes are opened = (1/x – 1/y). Time taken to fill the tank, when both the

pipes are opened = xy / y-x

iv.

If a pipe can fill a tank in x hrs and another can fill the same

tank in y hrs, then the net part filled in 1 hr, when both the pipes are opened

= (1/x + 1/y).

Time taken to fill the tank = xy

/ y+x

/ y+x

v.

If a pipe fills a tank in x hrs and another fills the same tank in

y hrs, but a third one empties the full

in z hrs, and all of them are opened together, the net part filled in 1 hr = (1/x + 1/y + 1/z)

time taken to fill the tank = xyz

/ yz + xz – xy hrs.

/ yz + xz – xy hrs.

vi.

A pipe can fill a tank in x hrs. Due to a leak in the bottom it is

filled in y hrs. If the tank is full, the time taken by the leak to empty the tank = xy / y-x hrs.

Here, we are providing some of

the examples on

questions and their solutions according to

the examples on

**pipes and cisterns**questions and their solutions according to

**bank**

exam.exam.

**EXAMPLE 1:**

Two pipes A and B can fill a tank in 36 hrs and 45 hrs respectively. If both

the pipes are opened simultaneously, how much time will be taken to fill the tank?

Two pipes A and B can fill a tank in 36 hrs and 45 hrs respectively. If both

the pipes are opened simultaneously, how much time will be taken to fill the tank?

Solution: part filled by A alone

in 1 hour = 1/36

in 1 hour = 1/36

Part filled by B alone in 1 hour

= 1/45

= 1/45

Part filled by (A+B) in 1 hour =

(1/36 + 1/45)

(1/36 + 1/45)

= 9/180

= 1/20

Hence both the pies together will

fill the tank in 20 hours.

fill the tank in 20 hours.

Direct method: by formula (iv)

Time taken = 36*45 /36+45

= 20 hrs.

**EXAMPLE 2: A**

pipe can fill a tank in 15 hrs. Due to a leak in the bottom, it is filled in 20

hours. If the tank is full, how much time will the leak take to empty it ?

pipe can fill a tank in 15 hrs. Due to a leak in the bottom, it is filled in 20

hours. If the tank is full, how much time will the leak take to empty it ?

Solution: Work done by the leak

in 1 hour = (1/15 – 1/20)

in 1 hour = (1/15 – 1/20)

= 1/60

Direct method by formula (vi)

Required time = 15*20 / 20-15

= 60 hrs.

**EXAMPLE 3:**

Two pipes A and B can fill a tank in 24 minutes and 32 minutes respectively. If

both the pipes are opened simultaneously, after how much time should B be

closed so that the tank is full in 18 minutes?

Two pipes A and B can fill a tank in 24 minutes and 32 minutes respectively. If

both the pipes are opened simultaneously, after how much time should B be

closed so that the tank is full in 18 minutes?

Solution: let B be closed after x

minutes. Then, part filled by (A+B) in x min. + part filled by A in (18 – x)

min = 1

minutes. Then, part filled by (A+B) in x min. + part filled by A in (18 – x)

min = 1

X ( 1/24 + 1/32) + (18-x) * 1/24

= 1

= 1

Or 7/96 + 18-x/24 = 1

Or 7x + 4(18- x)

= 96

Or 3x = 24

X = 8

So B should be closed after 8

min.

min.

Direct formula:

Pipe B should be closed after (1 –

18/24) * 32

18/24) * 32

8 min.

**EXAMPLE 4:**

If three taps are opened together, a tank is filled in 12 hrs. One of the taps

can fill it in 10 hrs and another in 15 hrs. How does the third tap work?

If three taps are opened together, a tank is filled in 12 hrs. One of the taps

can fill it in 10 hrs and another in 15 hrs. How does the third tap work?

Solution: We have to find the

nature of the third tap – whether it is a filler or a waster pipe.

nature of the third tap – whether it is a filler or a waster pipe.

Let it be a filler pipe which

fills in x hrs.

fills in x hrs.

Then, 10*15*x / 10*15+10x+15x

= 12

Or, 150x = 150*12*25x*12

Or -150x = 1800

X = – 12

-ve sign shows that the third

pipe is a waste pipe which vacates the tank in 12 hrs.

pipe is a waste pipe which vacates the tank in 12 hrs.

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