Two taps can separately fill a cistern in 10 min. and 15 min. respectively and when the waste pipe i

Maneesh Gupta   8 years AGO

time taken by tap1=1/10
time taken by tap2=1/15
time taken to fill the cistren together=(1/10+1/15)
=1/6
waste pipe time=1/6-1/18
=1/9
9 min
option 3) 9 minutes

Like? Yes (9) | No (1)  

RITESH KUMAR JHA   8 years AGO

1/15+1/10+1/x=1/18
1/x=1/18-1/15-1/10
from here x=9
so, third pipe empty the full cistern in 9 min..

Like? Yes (2) | No   

Shagun Chaudhary   8 years AGO

time taken by tap1=1/10
time taken by tap2=1/15
time taken to fill the cistren together=(1/10+1/15)
=1/6
waste pipe time=1/6-1/18
=1/9
9 min
option 3

Like? Yes (2) | No (1)  

MALLIDI PHANI MANOHARA REDDY   8 years AGO

let us take empty pipe can take x min...
Then 1/10+1/15-1/x=1/18=>x=9

Like? Yes (1) | No   

PAPAN SARKAR   8 years AGO

in 18 min both taps can fill 3 times the cistern , so waste pipe wipe out other 2 times cisterns water in 18 mins. so the ans is 18/2=9min

Like? Yes (1) | No   

ramarao   8 years AGO

both together fill in 6 min but takes 18 min due to leakage so it takes 9 min to empty the tank explanation in my Mobile is not easy

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Dasari sri Laxmi    8 years AGO

Total capacity of cistern is 90ltrs
1st can fill 9lit per min
2nd can fill 6lit per min
Both 1st, 2nd and 3rd can fill 5lit per min
Empty pipe consider as negative so
A+B-C=5lit/min
9lit/min+6lit/min-C=5lit/min
C=10lit/min
Total=90lit/(10lit/min)=9mints

Like? Yes (1) | No   

ABHINAV PUSHPAM   8 years AGO

let the time taken by the waste pipe be X min.
Then,
1/10+1/15-1/x= 1/18
1/x= 2/18
x= 9 min
option 3)

Like? Yes (2) | No (2)  

THUMMALA VINEESHA   8 years AGO

3 rd pipe can fill it in
(1/18)-(1/10)-(1/15)= -(1/9)
- represents the emptying
so option 3 ) 9min

Like? Yes (1) | No (1)  

yugeswar reddy   8 years AGO

both can fill the cistern in 6min, i.e (1/10+1/15). now when three is on,
waste pipe+both on=1/18.
but waste pipe is negative since filling is considered +ve.
so waste pipe =1/6-1/18 =1/9
so 9min.

Like? Yes | No   

vipin pandey   8 years AGO

1st pipe will fill the tank in 1min=1/10
2nd pipe will fill the tank in 1 min=1/15
both pipe will fill the tank together in 1 min =1/10+1/15=5/30=1/6
when the waste pipe is open then time taken together in 1 min =1/18
So the waste pipe can empty the full cistern in = 1/6-1/18=1/9
so total 9 min will be require to empty the cistern

Like? Yes | No   

monika mehta   8 years AGO

1/15 + 1/10 - 1/x = 1/18
where x is the time taken by waste pipe to empty the container separately
by solving it ...
x = 9

Like? Yes | No   

Gaurab Kumar Jha   8 years AGO

both taps together fill the cisten in 10*15/(10+15) = 6 min
a/q 1/18-1/6 = 1/9
therfore in 9 min waste can empty the cisten

Like? Yes | No   

Umang Jain   8 years AGO

x/18 - (x/10 + x/15)
x/18 - (3x+2x/30)
x/18 - x/6
-x/9 = 9 min

Like? Yes | No   

Ranganath   8 years AGO

Waste pipe draws the water.So work done by waste pipe must be subtracted from work done by two taps.

Like? Yes | No   

Richa Saini   8 years AGO

Let total volume of cistern be 'V'
Tap1 fill it completely in = 10 min
=> Volume of water in filled 1 min = V/10

Tap2 fill it completely in = 15 min
=> Volume of water filled in 1 min = V/15

Time taken to fill cistern full by both taps together be 't'
We can write it as= Total volume of cistern/ volume of water filled in 1 min
=> t= V / ((V/10)+(V/15))
By solving, we get t= 6 min

Time taken to fill cistern when waste pipe is open = 18 min
As we know cistern is filled in 6 min by both taps together.
So, in 18 min,cistern is filled 3 times ie. 3V volume of water.
After 18 min when waste pipe is open,cistern is filled completly with 'V' volume which means '2V' volume got released by waste pipe.

So waste pipe release '2V' volume in = 18 min
'V' volume released in = 18/2= 9 min
=> Cistern with 'V' volume emptied by waste pipe in 9 mins

=> option(3) is the answer.

Like? Yes (1) | No (1)  

Sudipa Chakraborty   8 years AGO

Let x be the time required by the waste pipe to empty the tank.
(1/10 +1/15)-1/x = 1/18
Or
1/6 -1/x = 1/18
Or
1/x = 1/6 -1/18
= 1/9
So, x=9 min

Like? Yes | No   

Shashank Rastogi   8 years AGO

bcoz
lcm of 10,15 and 18 is 90
then answer is 9.

Like? Yes (2) | No (2)  

deepak saroha   8 years AGO

combined speed of both taps=1/6 tanks/min
actual filling speed=1/18tanks/min
emptying speed=(1/6)-(1/18)=1/9tanks/min
therefore to empty full tank=9min

Like? Yes | No   

ARYA KRISHNAN G   8 years AGO

1/10 + 1/15 - 1/x = 1/18
(25/10*15) - 1/x = 1/18
1/6 - 1/x = 1/18
1/x = 1/18 - 1/6
1/x = 1/9
x = 9 min

Like? Yes | No   

S.MANJULA   8 years AGO

(1/10)+(1/15)-(1/c)=(1/18)
(1/6)-(1/c)=(1/18)
(1/c)=(1/9)
C=9 min

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sanjeet kumar   8 years AGO

Work done = 1/10 +1/15 -1/x
or, 1/10 + 1/15 -1/x = 1/18
Therefore, x= 9 minutes

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ruchika   8 years AGO

two pipe fill tank=1/6
two pipe + waste pipe=1/18
?1/6-1/8=1/9 I.e. 9 min

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P.Triveni   8 years AGO

Part of tank emptied by waste pipe in 1 minute=(1/10)+(1/15)-(1/18)=(1/9)
So,waste pipe can empty the cistern in 9 minutes.

Like? Yes | No   

NICHERLA JAYANTHRAMAN   8 years AGO

time taken by 2taps to fill the tank=(1/10)+(1/15)=1/6. time time taken by waste pipe to empty the tank=(1/6)-(1/18)=1/9=9min

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Devendra Marghade   8 years AGO

If waste pipe can empty in 'x' minutes, then 1 min. filling=
(1/10) +(1/15) -(1/x)=1/18
x=9
Option 3)

Like? Yes | No (1)  

MRITUNJAY   8 years AGO

work done when two inlet and one outlet is=1/10+1/15-1/18=1/9
time required to empty the full tank=9min
option 3

Like? Yes | No (1)  

PRABHAT KUMAR   8 years AGO

Time taken by waste pipe =1/18-1/10-1/15
=1/9
Time =9 minutes
Option 3

Like? Yes | No (1)  

Joseph Madanu   8 years AGO

together two taps fill the tank in 6mins((1/10)+(1/15)=1/6)
but they take 18min to fill with waste pipe
so ((1/6)-(1/x))=(1/18) ==>X=9mins

Like? Yes | No (1)  

Akshat Sood   8 years AGO

Total time to fill the cistern by both taps=1/10+1/15=1/6min
When waste pipe is open it takes 18 min for both taps to fill the cistern
Let time for waste pipe to empty the tank be x min
1/6+x=1/18
x=1/6-1/18=1/9=9min

Like? Yes | No (1)  

Mukund Manohar   8 years AGO

Work done by waste pipe in 1 minute=(1/10 + 1/15)-1/18
=(1/6 - 1/18)=2/18=1/9
So,the waste pipe can empty the full cistern in 9 minutes

Like? Yes | No (1)  

prem   8 years AGO

If we combine the work of 2 taps and waste pipe,then we get an equation and from that equation we get the required answer.

Like? Yes | No (1)  

chanukya   8 years AGO

A takes 10 mins and B takes 15 mins
LCM is 30 and we can assume that 30 lits as tank capacity
means (3-2)x = 18
capacity is 18 lits
if we left Pipe B 18/2 = 9mins

Like? Yes | No (1)  

Jamil Ahmed   8 years AGO

Both taps together can fill the cistern in 1/(1/10+1/15) = 6 min.

So, waste pipe can empty the full cistern in 1/(1/6-1/18) = 9 min.

Like? Yes | No (1)  

Anchal   8 years AGO

If we will add the two filling taps ans substract the total time

Time take to empty cistern = 1/10+1/15-1/18

Like? Yes | No (1)