Hello everyone, welcome back to a new video.
In today's video, our topic is Pipe and Cistern.
Whose corollary is this?
This is our time and work, which we had done in the
previous videos.
This video is on the concept of time and work, that is,
pipe and cistern.
What are pipe and cistern?
What will we do when we use this concept?
And how will we ask questions?
Basically, the questions in this video do not have any
concept of time and work.
And there are not many formulas in this video.
If you know the concept of time and work, then you can
easily do these questions on pipe and cistern.
So, what will we do on this?
First of all, you should know what is a pipe.
The theory that we should know in this is only a small
theory related to time and work.
I will tell you that.
Rest, there is no extra theory required in this.
So, what will happen in pipe and cistern?
Pipe will be your cistern.
Cistern means in which you are storing some storage of
water or some storage of liquid.
That would be your cistern.
So, if you are storing in any of these, let us suppose you
have this basket.
What are you doing in this?
What are you doing with the cistern?
You are filling water.
Now there will be some time to fill water.
And there will be some speed or efficiency of the cistern
to fill this bucket.
We will run this on the same concept of time and work.
Now, what are the cases in this?
The cases are normal.
That your water is coming from the cistern and it is
filling at some time.
So, wherever your water is coming from, there is an inflow.
What will we call that?
We will call that as an inlet.
What is happening in this?
Inlet of liquid is happening.
Means, water is coming inside.
Now, from somewhere, maybe our bucket is broken or there is
some leakage in it.
So, from where the water is going out of the cistern or any
of the basket, we will call that as an outlet.
Outlet means, what water is going to us from here?
It is going out to us.
You may not be able to see this.
So, what is this called?
Outlet.
Inlet means, there is an inflow inside.
Outlet means, our liquid or water that is flowing outside.
It is going out from here.
Whatever is given to us by the cistern.
So, what will we do in this?
I will tell you about work and time.
Let us revise that.
If, this concept will be on the same page.
If we are giving that, A is a person.
He did X amount of work.
Or suppose, he did X amount of work in T time.
T time.
T time can be in hours or minutes.
Whatever it is.
In T time, he finished his work.
He finished his work in time T.
So, what do we get out of that?
If he finished his work in T time, then in 1 hour or 1 hour
or whatever is 1 time minute.
In that, how much work is being done.
That means, how efficient is he.
Whatever work is being done in 1 hour, that is what is
called as his efficiency.
So, we get that out.
With the help of this, we further question.
There were cases in that.
If one person is working together with B, then how fast can
both of them work together.
And so on.
So, same.
In this case, what is going on? If he is finishing his work
in T time, then what do you do?
In 1 time, how much work can he do?
How do you find that out?
Work done in.
Work done in 1 hour.
What do you do?
You do the opposite of this.
You do this.
1 by T, amount of work.
That means, in 1 hour, if a person is taking T time,
suppose a person is taking 10 hours to finish a work, then
in 1 hour, how much work can he do? 1 10th of the work.
Whatever is 1 10th part of the work, he will finish it in 1
hour.
So, we will do the same thing in pipe and cistern.
In this, what will happen?
If there is a certain pipe, this is a pipe or anything,
inflow.
Wherever the liquid or water is inflowing, we will see that.
If a pipe, is doing one work, means one pipe, pipe A,
is filling this basket in
X hours.
Pipe A is filling
this whole, full basket in 1 hour.
It takes X hours to fill this basket completely.
So, what we will find out is, in 1 hour, how much portion,
how much portion of this bucket can be filled by this pipe?
In 1 hour, how much portion of this basket can be filled by
this pipe?
We can find that out.
What will we do?
We will do 1 upon X, 1 upon time.
So, what will we get?
Part, amount of, or part whatever it is, part filled, pipe,
basket in, how much?
In 1 hour, so what will happen? Part of, basket, or
whatever it is, basket, bucket, part of bucket filled in 1
hour would be nothing but the reciprocal of this.
So, how much will it be? 1 by X.
What is this much portion of this bucket being filled?
Filling of this bucket in 1 hour.
In 1 hour, this much work is being done.
As we used to take work done in this, in this, what is the
work being done?
Filling of this bucket.
So, we have written that in the language.
You just have to keep this in mind.
If you are given the amount how much work you have done,
then if you reciprocalize it, time will come. If you
reciprocalize time, work done will come.
We will go on the same page.
So, we don't have to look at the SHM.
If only that.
What will be your case?
You have 2 pipes.
And both the pipes with some speed or efficiency are
filling one bucket.
So, both together, if we turn on both the taps together,
then how much time will it take to fill this bucket?
So, what we will do?
We will take out the work done of this.
We will see the efficiency of this.
Work done means how much part is being filled in 1 hour.
And how much part is being filled in B1 hour.
We will add that.
And then if the work done of 1 hour comes, then we will
reciprocalize it.
As soon as we reciprocalize it, what will we get?
We will get time.
What will be the reciprocal of work done?
Time. So, they are taking that much time to fill this
bucket together.
This is one case.
Now, this is a cup case.
Now, both the taps are filling it.
But, we have another case.
The second case is of leakage.
If there is a leakage or water is coming out of it.
Like you are filling a bottle with RO.
So, 1 to 2 RO taps will fill the water in that bottle or in
that bucket.
And, if you have one more tap of RO bottles on the side to
take water.
So, you are taking one glass of water or one bottle of
water.
So, what is coming in this?
Are both the things happening simultaneously?
One is your inflow and on the other hand, the tap here.
What is happening with that?
If you are drinking water, there is an outflow of water.
So, in that case or in the case of leakage, in the case of
leakage or in the case of outflow of water, we will simply
put it in that work.
Like it was minus when we put it together.
Sorry, it was plus.
In that case, it will be minus.
So, what will the minus sign refer?
That what is happening with you?
Your system or your bucket.
And, what will the plus sign indicate? That you are filling
that thing.
So, the plus sign is filling and the minus sign is empty.
So, this is not much of your theory. This is the theory
which we will learn little by little. Whatever is used, we
will do it on questions.
Then, you will get to know from the questions.
So, look at the question.
The first question is
Question says, two pipes can fill a cistern separately in
10 hours and 15 hours.
So, if we have two pipes, then A is taking 10 hours and B
is taking 15 hours.
So, they can together fill the cistern.
Do you remember this question?
Does anyone have similar or analogous type of question?
Who has the same type of question that you had asked in the
work done?
That if one person and two persons are working together,
A person is finishing the work in some time, and B person
is finishing the work in some time.
So, both of them together, how many hours or days they will
finish the work together.
This question is on the same line.
So, if we are given about A and B, then we have to see how
fast they will fill the cistern together.
So, if A is taking 10 hours to fill this, then how much
time will it take to fill in 1 hour? 1 by 10, 1 by 10th
part of the cistern.
Means, the whole part of the cistern,
A is taking 1 hour.
So, A is filling 1 by 10th portion of the whole cistern in
1 hour.
Similarly, if we see B, then how much time will it take to
fill in 1 hour? 1 by 15th, you have to simply reciprocate
the time.
So, what is 1 by 15th part doing?
B is filling, 1 by 15th part of the bucket.
So, A is doing this much work, B is doing that much work in
1 hour.
What we have to see is, if both of them do the work
together, so, if I see the work of both of them together in
1 hour,
I will add the efficiency.
So, A and B, means, how much work is being done in 1 hour,
what will happen is, simply add the efficiency of A with
the efficiency of B.
Efficiency of A and efficiency of B, what do I call
efficiency?
You must have seen it in time and work.
Whatever work you are doing in 1 hour, that would be your
efficiency.
So, if you do efficiency of A and efficiency of B, then
efficiency of both of them will come.
So, how much will it come after solving? 10, if you are
taking 150, then 15 plus 10, that is 25.
And then subtract it, 1 and 4, 5, 6.
1 by 6.
So, 1 by 6 amount of work, they both are doing together in
1 hour.
So, if 1 by 6 portion of work is being done by them, if
they are working together, then in 1 hour, they are able to
fill 1 by 6 portion of this bucket or system.
So, how much time will it take?
If in 1 hour, 1 by 6 is being done, in 2nd hour, add 1 by 6
more.
So, how much time will it take in total?
Reciprocal.
So, total time taken, total time taken, by A and B
together, would be reciprocal of this, that would be 6
hours.
So, what will be the answer of this? 6 hours.
It was easy.
On which line are you following?
You are following the same path, which we followed in work
and time.
Nothing else.
If you ask about both together, and see, both are filling
both pipes, that's why I have added here, because both are
being added.
In which they are helping?
In filling.
How will there be a sign in filling?
First, sign of plus.
Next question.
I hope you are getting this clear.
We are going on the same line.
We are not doing anything different.
When we will do, I will let you know.
So, read this question first.
What is the question? 2 pipes can fill a tank,
Again, we are talking about 2 pipes in starting.
2 pipes can fill a tank in 10 hours and 12 hours
respectively.
A is filling in 10 hours.
And B is filling in 12 hours.
Complete fill.
Tank.
They are filling the tank in 10 hours and 12 hours.
So, what is the efficiency of A? What will be the work done
in 1 hour? 1 by 10. It is filling 1 by 10th portion.
It is filling 1 by 10th portion in 1 hour.
Similarly, how much work is B doing in 1 hour?
B is filling 1 by 12th portion.
Then, while a third pipe, What is it doing in this much
time?
Third pipe is emptying the full tank in 20 hours.
Take a pipe C.
It is emptying the tank.
These two were filling.
What is C doing?
It is emptying the same tank.
So, what is C's efficiency?
C is filling in 20 hours.
So, what is C's efficiency?
How much work is C doing in 1 hour?
C is emptying 1 by 12th portion in 1 hour.
The efficiency of these people was 1 by 10 and 1 by 12.
It means, they are filling this much portion.
But, what is C doing in this 1 by 20th portion?
It is emptying this much portion in 1 hour.
So, what we have to show is,
If all the three pipes operate together,
Now, what did these three pipes do at the same time?
They switched it on.
So, in how much time the tank will be filled?
Here, the concept of Minus came.
What we have done in Together,
What you have to do in that is,
Efficiency of A plus efficiency of B.
Now, you have the third pipe C.
So, if you have A, B and C,
These three pipes working together,
They are working together.
So, what will happen?
If I add efficiency of A and efficiency of B,
Because, what are they doing?
They are filling the tank.
But, what is C doing?
It is emptying it.
It is outflowing.
So, in front of its efficiency,
You don't have to do anything.
You just have to put a minus sign.
You have to keep this in mind.
Minus sign. Negative.
Because, what are they doing?
They are emptying it.
But, if there was a leakage,
If there was a leakage instead of emptying,
Then, we would have put a minus sign.
Nothing else.
So, we have put a negative sign.
Now, what we will do is,
We will solve it.
Solve it further.
Shall I erase this?
Solve it.
What will it be? 2400.
I am not taking LCM.
I am simply solving it.
So, it will be above 10.
12 into 20.
That is 240.
Plus 12.
So, it will be 200.
Minus 20.
That is 120.
It is 120.
Solve it.
You will get 440 minus 120.
That is 320.
Divided by 2400.
8 x 4 and 8 x 3.
Combined efficiency of all three.
Combined work done of all three.
2 x 15.
If you combine all three,
Then, it is emptying and filling at the same time.
So, the portion which they are filling,
Since, the answer is in plus,
It is the efficiency of filling.
So, your 2 x 15th portion.
2 x 15th portion is being filled in 1 hour.
Since, we were doing efficiency of 1 hour only.
So, if it is so much in 1 hour,
How much time will it take?
If I reciprocate it,
How much time will it take?
Time taken to fill.
When all three are together,
That would be 15 x 2 hours.
15 x 2 will be 7.5.
That is 7 hours and 30 minutes.
So, how much time will it take? 15 x 2 hours.
And if we ask in minutes, 7 hours and 30 minutes.
Whatever combined work is being done,
Or time is being filled,
So, how much time will it take?
Okay? What did we learn in this question?
Now moving on to next question. Read this once.
So yeh wala question aap dekhiye.
Pipe A can fill an empty tank in 6 hours.
Pipe B can fill an empty tank in 8 hours.
So efficiency of Pipe A will be 1 sixth portion in 1 hour.
Similarly Pipe B can fill an empty tank in 1 eighth portion
in 2 hours.
If both the pipes are opened and after 2 hours.
Kisi certain hours ke baad, kisi certain time frame ke baad
A is closed.
To ab se B chal raha hai.
How much time B will take to fill the remaining tank? Aap
ke paas yeh tank hai, idhar se A ka paani aa raha hai,
idhar se B wale tap ka paani aa raha hai.
2 ghante baad yeh kuch bhar jaayega, dono ki help se
bharega woh 2 ghante baad.
Ab yeh aapne close kar diya, ab jo baaki itna remaining
portion bach raha hai.
Woh kaun fill karega?
Woh sift tap B fill karega.
Kyonki A to humne ban kar diya hai.
To woh kitna time lega to fill this portion?
Woh hum dekhte hai.
Dekhiye A ki efficiency nikaali, B ki efficiency nikaali.
To ek hour mein dono mila ke kitna kaam karenge?
A and B together ek hour mein kitna kaam karenge? 1 sixth
plus 1 eighth itna woh fill kar lenge ek hour mein.
To yeh kitna ho jayega? 7 to 8, 48, 6 plus 8, 14, cancel
karke kitna aa raha hai yeh? 2 sevenths a, 20, fourths a,
to yeh aa gaya 7 by 24.
7 by 24th portion woh fill kar raha hai in 1 hour.
But yeh inko kitne hours tak open gaya tha? 2 hours tak? To
yeh dono mila ke 2 hour mein kitna kaam kar lenge?
Agar ek hour mein yeh itna portion fill kar rahe hain, to 2
hour mein iska double portion fill kar lenge?
To 2 hours mein kitna fill kar rahe hain portion?
That is 2, 7 on 24.
To that would be your 7 by 12th.
Itna portion yeh kya kar rahe hain?
They are filling in 2 hours.
Itna portion yeh 2 hours mein mila ke fill kar rahe hain.
Matlab agar aapke paas aadi se zyada kaam to yeh ho gaya? 6
by 12th wadha half portion hota 50%.
To yeh aapka 7th woh usse zyada hi ho gaya 50% se zyada.
Now, the remaining portion, woh kiske zimmiye de rakha hai
sirf?
Woh sirf B-TAP ke zimmiye de rakha hai.
To woh kitti der mein fill karega?
To sabse pehle to aap kya dekhenge ki remaining portion
aapka hai kitna? Tabhi to aap uska nikal payenge ki woh
kitna time le raha hai.
Kya ho gaya hai is raster ko?
To yeh 1 hour ka hata deti hoon.
Yeh haan tak aapka ho gaya.
2 hours tak ki kahani hai aapki.
Yeh haan tak kya ho gaya?
Complete ho gaya.
That is this.
2 hours tak yeh itna fill ho gaya hai.
Then, hum kya karenge? Hum pehle likhenge remaining portion.
Remaining portion.
Remaining portion kab? 2 ghante ke baad jitna bacha?
After 2 hours.
Kaunse 2 hours?
Jab woh dono saath mein on the tab kitna portion bachega?
To full part hota hai 1.
Agar hum poora dekhe to 1 aur yeh fraction hai.
To kya karenge? Hum remaining portion nikalne ke liye 1 se
is portion ko kya kardenge? Subtract kardenge.
To yeh karo LCM aajega 12.
12 minus 7, 5.
To yeh aajega 5 by 12.
Itna portion kya hai aapka?
Left over portion.
Itna portion aapko kya karna hai?
B ne akele fill karna hai.
Ab B jo hai woh akele ek ghante mein kaam poora kar raha
hai.
Ek ghante mein.
Woh kar deta.
Agar woh ek ghante mein, 8 hours mein kar raha hai.
To matlab woh ek poora portion.
Jo whole portion hum le raha hai.
Usko kitne time mein kar raha hai? 8 hours mein.
But ab usko kitna portion karna hai? 5 by 12.
Yeh matlab nahi hai ki yeh 1 se chota hai ya 1 se bada hai.
Agar humein 1 ke liye value given hai.
Ki 1 portion, 1 portion, 1 ya part.
B kitne mein kar raha hai? 8 hours lekar.
To itna portion woh kitne mein karega? 5 by 12 portion kaam
woh kitne mein karega?
Obviously, into kar do 1 wali cheez se.
To 5 by 12 into 8.
Yeh kya ho jayega aapka?
Ki kitna time woh le raha hai to complete this portion.
To solve karo, yeh kitna ho gaya aapke paas?
Yeh ho gaya aapke paas? 4 2's, 4 3's.
This would be your 10 by 3.
Hours aa raha tha iss se, to 10 by 3 hours.
So, B jo time le raha hai.
Woh le raha hai, 10 by 3 remaining portion ko fill karne
mein.
Isko aap mixed fraction mein likh le na.
Yeh hi pe chod do, jo bhi aapko option mein given ho ga.
To samajh aayi baat humne kaise kiya?
Humme A aur B ka humne together tak kiya.
2 gante ka kaam tak unka saath tha.
2 gante ke baad ek ka saath choot gaya.
Sirf B raha gaya, uske zimme.
To uske le, kitna kaam bacha? Pehle hum woh to dekh le ki
kitna kaam isne aur karne hai.
To woh humne nikal le ki itna portion isne aur fill karne
hai.
To uski 1 hour ki efficient, jo 1 portion bhar raha tha.
To woh 8 hours mein bhar raha tha.
Malab ek poora basket hota tha, woh 8 gante laga tha.
To jitna bhi yeh portion hai, yeh kitne mein bharega? 1
wale sam, into kar do.
To 1, 8 se into kar diya, answer aagaya.
Hours mein.
Ki remaining portion bhi kitne mein fill karega? 10 by 3
hours.
Now, moving on to next question.
To isme humne kya seekha?
Is question mein new cheez kya thi?
Ki agar koi certain time ke baad aapka kuch leakage ho jaye
ya kuch ek tab ko ban kar denge ya koi extra add ho jayega,
tab hum kaise nikalenge?
To woh hum aise aise karke nikalenge.
Simple.
Read it.
There are 2 tabs to fill a tank.
Phirse 2 pipes ki baat ho rahi hai, tabs ki baat ho rahi
hai.
Ek pipe A.
Pipe A is 3 times.
3 times faster than pipe B.
Pipe A jo hai, wo 3 times faster than pipe B hai.
To is bar humein yeh time kuch nahi bataya ki
A itna time mein kar raha hai, B itne time mein kar raha
hai.
Humein unka kya de diya?
Humein unka wo de diya, relation.
Ki wo 3 times faster hai than B.
To agar, agar wo tez kaam kar raha hai, pipe A.
Agar tezi se kaam kar raha hai, to matlab wo kaam jaldi
finish kar lega.
Uska kaam kya hai abhi?
Paani bharna.
To agar humne pipe A, agar pipe A humara jo hai, wo faster
hai, to matlab wo jaldi se fill kar lega tank ko, aur B
slowly fill karega tank ko. To let kar lete hain.
Let time taken, time taken by pipe A to fill the tank.
Likh lena poori, to fill the tank bhi T hours.
T hours lete hai ki usko T ghante lag rahe hain to fill
this, to fill the tank.
To agar usko T hours lag rahe hain, to isko pipe B, pipe B.
time to fill the tank.
How long will the slower pipe take to fill the tank?
How much portion will it take to fill the tank?
That is 1 by T portion.
Similarly, how much portion will it take to fill the tank
in one minute? That is 1 by 3 T portion.
Both are filling the same portion.
So, how much portion will they fill together? 1 by T plus 1
by 3 T.
How much portion will they fill together? Filled by A and B
together.
How much portion will they fill together in one minute?
So, if you want to see 36 portion, then 1 by 36 will be
equal to 1 by 36.
Now, solve this.
Take this LCM, this would be 3 T.
So, here we have to multiply by 3.
3 plus 1, that would be 4.
So, this will be 4 upon 3 T.
So, 1 by 36 would be 4 upon 3 T.
So, this will be, what happened?
It got cancelled.
12.
And take T here.
So, what is T? 12 into 4.
That is 48 minutes.
What is the value of T? 48 minutes.
So, whose time was T?
Pipe A's.
Pipe A is taking 48 minutes to fill the tank.
So, how much time will Pipe B take? 3 T minutes.
That is 3 into, what will happen to you? 3 into 48 minutes.
Multiply by 3.
8 is 24.
3 by 4 is 12.
So, how much time will Pipe B take to fill the tank? It
will take 144 minutes.
And see, how fast it was doing it.
It was doing it in 48 minutes.
Obviously, it will do it fast because its speed is so fast.
It is fast.
Water is coming out of it fast.
So, this was a new type of question for you.
Okay? This was also a new type.
Next, last question.
Last question for this video.
Let us see what is there in this.
So, we will read this question.
What is this question saying?
We are talking about 3 pipes.
3 pipes A, B and C can fill a tank in 6 hours.
A, B and C are filling a tank together in how much time?
They are filling it in 6 hours.
So, A plus B plus C are filling the tank together in 6
hours.
So, when their time is given to fill the tank, will you
take out the efficiency of all three of them together?
Means, in 1 hour, how much efficiency will they do in 1
hour?
How much efficiency will they do in 1 hour?
They will do 1 by 6 portion.
They are filling the part.
If they are filling 1 by 6 portion in 1 hour, then only
they are filling it completely in 6 hours.
After working together for 2 hours,
C is closed and A and B can fill the remaining part in 7
hours.
What did these three do for 2 hours?
They worked together.
After that, C is closed.
Then, the remaining portion which is left to fill, A and B
worked together in 7 hours.
So, the number of hours taken by C alone,
How much time will C alone take to fill the tank?
We have to find out that time.
If A, B and C are working together for 1 hour, then they
worked together for 2 hours. So, in 2 hours,
These three,
In 2 hours, how much portion will they fill?
Obviously, they will be able to fill double portion.
Because, in 1 hour, they will work twice as much.
So, they will fill 2 into 1 by 6 portion.
That is, they are filling 1 third portion in 2 hours.
In 2 hours, 1 third portion is filled.
The remaining portion, How much portion will be left to
fill? The remaining portion will be,
Remaining portion,
Remaining, What will happen?
If I subtract 1 by 3 from 1,
In the last question also, we had done the remaining
portion.
If you take the whole portion,
Like, 1 third portion is filled.
If you subtract this much,
Then, you will get the remaining portion.
That is, 2 third.
So, what is the remaining 2 third portion?
Now, who will fill it?
Now, they will fill A and B together.
Because, C has left.
So, how much portion are A and B filling together?
A and B, together, 7 hours.
They are taking 7 hours to fill,
The remaining portion, which is 2 third portion.
They are filling this much portion in 7 hours.
If they are filling this much portion in 7 hours,
We have to find the number of hours taken by C alone.
How much time will C alone take to fill this whole tank?
From start to end.
How much time will C alone take to fill this whole empty
tank?
If we subtract that,
How will we subtract?
If, see, what is given to us?
A, B and C,
How much time are they taking to fill this whole empty
tank? 6 hours.
So, efficiency of 1 by 6 is taken out.
So, if we get to know about A and B,
How much time will they take to fill this whole tank?
So, efficiency will be taken out.
So, we will get to know about A and B,
How much time will they take to fill this whole tank?
So, when that comes,
If we subtract efficiency of A, B and C,
So, how much time will they take to fill this whole empty
tank?
How much time will they take to fill this whole empty tank?
we will get the efficiency of C only, that he is working so
efficiently in such a short time. So, we have to find out
that only. So,
see that A plus B is taking 7 hours to fill 2 third
portion. So, we have to see the whole portion. If he has
the whole tank to fill, then how much time will they take?
So, he is taking 2 third portion.
How can you write this?
To fill 2 third portion, you are taking 7 hours.
So, how much time will it take to fill 1 portion? 7 divided
by,
If you do 2 by 3, then we will divide by 2.
If we divide by 3, then it will go to the upper multiply.
We are taking out so many hours.
So, this would be your 21 by 2 hours.
To completely fill the tank.
If A and B were filling the tank from the starting, then
how much time will they take? 21 by 2 hours, that is 10.5
Means, they will take 10.5 hours to fill this tank
completely.
Now, we have to find out C alone.
We have to find out C alone.
So, what will be the result?
A plus B plus C of all three.
This is their efficiency.
Minus, if you take out the efficiency of A plus B.
Now, A plus B is taking so much time to fill.
So, how much will be their efficiency?
Reciprocal of time, that would be 2 by 21.
So, how much is the efficiency of A, B and C? 1 by 6.
Efficiency is taken out in one hour.
How much will be the efficiency of A and B? 2 by 6.
Means, they are taking the entire time.
It is taking 6 hours to fill the tank completely.
So, we have taken 1 by 6.
To fill the tank completely, they are taking 21 by 2 hours.
So, we will reciprocal of time.
2 by 21.
If we subtract, then the time of C alone will be taken.
So, what will be the result?
If you solve this.
So, 6 into 21.
So, 21 minus 12.
This would be your 8, 9, 6 by 21.
So, what will be the result? 3 by 2, 3 by 3.
So, 3 by, how much is the answer? 3 by 20.
This will also be cancelled.
So, what will be the result of 1 and 7? 1 by 2 into 7.
That is 1 by 14.
The efficiency of C is 1 by 14.
It is filling this much portion in one hour.
So, what do you want?
You have to tell the time taken.
How much time will it take?
So, you reciprocal of efficiency.
That is 14.
So, how much time will it take to fill this? 14 hours.
If C is filled alone, then it will take 14 hours to fill
this tank completely.
So, I hope whatever theory we did today, we did nothing.
We just related it with time and work.
And all these 5 different questions we did, I hope you will
be clear.
And you will be able to do practice questions of pipe
assistance easily.
Thank you for watching the video.
See you in next.
I'll make sure to spread the word to all my classmate.