Latest TCS Aptitude Question SOLUTION: Three pipes, A, B, & C are attached to a tank. A & B can fill it in 20 & 30 minutes respectively while C can empty it in 15 minutes. If A, B & C are kept open successively for 1 mi

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(#M40152877) TCS Numerical Ability question TIME AND WORK Keep an EYE

Three pipes, A, B, & C are attached to a tank. A & B can fill it in 20 & 30 minutes respectively while C can empty it in 15 minutes. If A, B & C are kept open successively for 1 minute each, how soon will the tank be filled?

Asked In TCS vaishali rathore (8 years ago)

Solved Prasit Chakraborty Read Solution (24)

Is this Puzzle helpful?   (26)   (8) Submit Your Solution Time and Work

Read Solution (24) :

mahesh  (8 years ago)

in three minute 1/20+1/30-1/15=1/60 part is filled
3 min--------1/60 parts
x min--------- 1 part(full)

x=180 min =3 hours

Is this solution Helpfull? Yes (34) | No (8)  

Prasit Chakraborty  (8 years ago) Best Solution

Time to fill the tank by pipe A = 20 minutes

so part of tank filled in 1 minute by pipe A = 1/20 per minute

Time to fill the tank by pipe B = 30 minutes

so part of tank filled in 1 minute by pipe B = 1/30 per minute

Time to empty the tank by pipe C = 15 minutes

so part of tank emptied in 1 minute by pipe C = 1/15 per minute

So if all the pipes works successively ,

part of tank filled in 1 minute = 1/20

part of tank filled in 2 minute = 1/20 + 1/30 .

part of tank filled in 3 minute = 1/20 + 1/30 - 1/15

=1/60

so after 165 minutes =(165/3)x(1/60) =55/60

after 166 minutes =55/60+1/20=58/60

after 167 minutes =58/60+1/30=60/60

So the answer is 167 minutes

Is this solution Helpfull? Yes (27) | No (48)  

Shivam Singh Rathore  (8 years ago)

First of all take L.C.M. of 20,30 and 15 it will give you total size of tank i.e. 60 then divide 60 to 20 it will give how much unit A can fill the tank in 1 minute i.e. 3 unit per minute same as B can fill 2 unit per minute and c can empty 4 unit per minute and then
A+B-C= 3+2-4 = 1 unit in three minutes because pipes will keep open successively for 1 minute
so 60*3 =180 minutes

Is this solution Helpfull? Yes (9) | No (4)  

Pooja kumari  (8 years ago)

ans=60 min
work done=1/20+1/30-1/15=1/60
s=60 min

Is this solution Helpfull? Yes (8) | No (9)  

kamireddy hemalatha  (8 years ago)

L.C.M of 20,30,15 is 60.
So total capacity of tank is 60 l.
So A fills 3 l in 1 minute.
B fills 2 litres in 1 minute.
C sends 4 liters in 1 minute.
So 2+3-4=1
So water in tank is 1liter per 3 minutes.
So to fill 60 liters 180 minutes.

Is this solution Helpfull? Yes (7) | No (2)  

aliza  (8 years ago)

tank filled in 1 min=(1/20+1/30)-1/15
=5/60-1/15
=1/60

Is this solution Helpfull? Yes (6) | No (2)  

rabi  (8 years ago)

let 180unit work
A,B,C haveing spd 9,6,12 unit per min
now 9+6-12=3 unit
then 180/3=60
take 59 whch is almost 60
59*(9+6-12)=177unit and time=59+59+59=177
at 178 th min A would open and fill the tank fully
ans=178min

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prabin jain  (8 years ago)

60 minutes

Is this solution Helpfull? Yes (3) | No   

Ankan dey  (8 years ago)

180 min
first A is filling the tank then B then C empty it..so total 3 mins=1/20+1/30-1/15=1/60
So in 1 min=60 x 3=180 mins

Is this solution Helpfull? Yes (2) | No (2)  

kailas sharma  (8 years ago)

in 1 minute the tank fill 1/60.
so the tank takes time to fill fully is 60 minute means 1 hour.

Is this solution Helpfull? Yes (2) | No   

sunil kumar  (8 years ago)

A , B & C = 60 min

Is this solution Helpfull? Yes (1) | No (1)  

redblood  (8 years ago)

A can filled in 20 min that means A can filled 5% per min
B can can filled in 30 min that means B can filled 3.33% per min
c can empty it in 15 min that means C can empty 6.66% per min
so all three are open successively for 1 min each
so tank fill after 3 min=(A's fill+B's fill-C's empty)=(5+3.33-6.66)=1.67% tank fill in 3 min
1 min tank fill=1.67/3=0.556%
100 % tank fill in =100/0.556=179.86 min ans.

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sagar kumar  (8 years ago)

if we consider all are opened at same time then they will fill in 60 min........... but if we consider one after other then in 3 min they will do 1/60 work done in 3 min .so whole would we done in 180 min

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ROHIT KUMAR  (8 years ago)

Tank filled in 1st minute = 1/20
Tank filled in 2nd minute = 1/20 +1/30
Tank filled in 3rd minute = 1/20 + 1/30 - 1/15
Amount of water in Tank after 3 minutes = 1/60
Hence total time needed to fill the tank = 3*60 = 180

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bhalla ram  (8 years ago)

why ? after 165 minute

Is this solution Helpfull? Yes | No (1)  

Prashant  (8 years ago)

I think nearly equal to 69 minutes.

Is this solution Helpfull? Yes | No (1)  

raghavendra prasad  (8 years ago)

why ? after 165 minute

Is this solution Helpfull? Yes | No (1)  

Aniket Waghamare  (8 years ago)

in 1 min.A fills 1/20 part
B fills 1/30 part and C empty 1/15 part
If pipes used successively after 3 min part filled is
1/20+1/30+1/15=1/60 i.e. one round...
therefore after 59 round part filled is 59/60....and total min required for that is 59*3=177 min.
and then in next minute pipe A fills the tank fully
thus total min required are 178 minutes..........

Is this solution Helpfull? Yes | No (2)  

AJEESH K U  (8 years ago)

what is the correct answer?
Admin plz provide it?

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Ramya Dasari  (8 years ago)

in first minute A fills 1/20 part of tank
in second minute A & B fills 1/12part of the tank
in third minute A,B & C fills 1/60 part of the tank
so,totally after 3 minutes the fills (1/20 + 1/12 + 1/60) part of the tank =9/60 th part of the tank
then to fill full tank is 20 minutes ( 60/9 x 3/1 = 20)

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SatB  (8 years ago)

work done by a in 1 min = 1/20
work done by b in 1 min = 1/30
work done by c in 1 min= 1/15
so portion filled in 1 min = (1/20 + 1/30)-1/15 = 1/60
1/60 part filled in 1 min
so 1 part filled in 60 mins = 1 hr

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jyotshna bhardwaj  (8 years ago)

In three minute 1/20+1/30-1/15=1/60 part is filled
3 min--------1/60 parts
so left part =(1-1/60)
left part=59/60
if 1/60 part can be filled in 3 mins
59/60 part can also be fill in (3*60*59)/60=177
so total time take by A,B,C pipes=177+3=180

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santosh singh  (8 years ago)

Total work done in 3min=3+2-4.....means 1unit.....so to do 60unit of work it is required total 180min

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jujara kumar  (7 years ago)

( 1/20 + 1/30 - 1/15 )= 1/60 for 3 minutes
so 3*60 = 180 minutes

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