Latest TCS Aptitude Question SOLUTION: An empty tank be filled with an inlet pipe "A" in 42 minutes. After 12 minutes an outlet pipe "B" is opened which can empty the tank in 30 minutes. After 6 minutes another inlet pi

• Placement Papers
• /
• TCS

TCS Question Papers: TCS Interview Experience(90) TCS Company Profile

(#M40029706) TCS question Keep an EYE

An empty tank be filled with an inlet pipe "A" in 42 minutes. After 12 minutes an outlet pipe "B" is opened which can empty the tank in 30 minutes. After 6 minutes another inlet pipe "C" opened into the same tank, which can fill the tank in 35 minutes and the tank is filled. Find the time taken to
fill the tank?

Asked In TCS pre (10 years ago)

Solved Gaurav kumar Read Solution (13)

Is this Puzzle helpful?   (5)   (2) Submit Your Solution

Read Solution (13) :

Gaurav kumar  (10 years ago)

let after the 3rd inlet is added tank is filled in x min
so first inlet will work for (x+18) similarly second outlet for (x+6)
now why 100/42 its because in 42 min it fills 100% so in 1 min 100/42..
so in (x+18)min it will work (X+18)*100/42
similarly in (x+6)min second outlet will work (X+6)*100/32
(x+18)*100/42 - (x+6)*100/30 + (x)*100/35 = 100
therefore x = 40.5
so time to fill the tank = 40.5+18 = 58.5

Is this solution Helpfull? Yes (16) | No (1)  

chandan kumar  (10 years ago)

let a ,b and c pipe
a can fill the tank in 42 minutes.
then in 1 minute it can fill 1/42.
in 12 minute (1/42)*12=2/7.
next 6 minute a can fill (1/42)*6=1/7
and b can remove (1/30)*6=1/5
then in 18 minutes tank filled=2/7+1/7-1/5=8/35
1-8/35=27/35 remain for filling
in 1 hr a,b,c can fill
1/42+1/35-1/30=2/105
2/105 can fill in 1 minute
then 27/35 can fill in 40.5 minute.
18 minute is also then
40.5+18=58.5 minutes

Is this solution Helpfull? Yes (14) | No   

Faizulla Khan  (10 years ago)

x/42-(x-12)/30+(x-18)/35=1.
4x-24/210=1
4x-24=210
4x=234
x=58.5

Is this solution Helpfull? Yes (7) | No   

bhagyashree roy  (10 years ago)

ans is 58.5 min

Is this solution Helpfull? Yes (6) | No (1)  

ATIQUR RAHMAN  (10 years ago)

ans is 58.5 min.

Is this solution Helpfull? Yes (4) | No   

Aritra  (10 years ago)

let a ,b and c pipe
a can fill the tank in 42 minutes.
then in 1 minute it can fill 1/42.
in 12 minute (1/42)*12=2/7.
next 6 minute a can fill (1/42)*6=1/7
and b can remove (1/30)*6=1/5
then in 18 minutes tank filled=2/7+1/7-1/5=8/35
1-8/35=27/35 remain for filling
in 1 hr a,b,c can fill
1/42+1/35-1/30=2/105
2/105 can fill in 1 minute
then 27/35 can fill in 40.5 minute.
18 minute is also then
40.5+18=58.5 minutes

Is this solution Helpfull? Yes (4) | No   

Pratyusha Bhadra  (10 years ago)

ans. is 58.5 mnts

Is this solution Helpfull? Yes (3) | No (1)  

Harshit Agarwal  (10 years ago)

A(1st inlet pipe) fills in 42mins so its rate of doing work 100/42= 2.38%
B(outlet pipe) empties with %age 100/30=3.33%

now A first works for 12mins so %age filled by A is 2.38*12=28.56%
then it works for 6 mins so %age filled again by A is 2.38*6=14.28%

meanwhile B(outlet pipe)was also working for 6 mins ,
so its rate of emptying is 3.33*6=19.98%

So net work done till 18mins is (A for 12mins)+(A for 6 min)-(B for 6 min)
=28.56+14.28-19.98= 22.86%
so remaining is 100-22.86=77.14%

now A+B+C together fill in 2.38%-3.33%+2.85% i.e. 1.9%
this 1.9% is filled in 1 min
so remaining 77.14% will be filled in 77.14/1.9 i.e. equal to 40.6 min
hence the total time taken will b 40.6+18 i.e. 58.6min
ans =58.6min

Is this solution Helpfull? Yes (3) | No (2)  

ak  (10 years ago)

is ans = 32 min..............
verify

Is this solution Helpfull? Yes | No (4)  

ranjit mangaraj  (10 years ago)

take lcm of 42 min and 30 mn which will give capacity 420liter
now inlet pipe rate is 10 l/m and out let has 14 l/m so
inlet opned for 12 minute fill 120 liter and then out let pipe com which out water 14 liter /m then (14-10) i.e 4 liter reduced per minut from 120 liter for 6 minute=24 liter
120-24=96 liter left
then another inlet comes whose rate is 324/35=27 minute (420-96=324)
ans 27 minute

Is this solution Helpfull? Yes | No (3)  

Manasa Nikitha  (10 years ago)

hey could u please make it clear???

Is this solution Helpfull? Yes | No   

swati  (10 years ago)

Assume total tank capacity = 210 Liters Now pipe A fill this tank in 210/42 = 5 min B empties this tank in 210 / 30 = 7 min C fills this tank in 210 / 35 = 6 min Assume tank gets filled in x min. So x × 5 - (x-12)×7 + (x - 18) × 6 = 210 ⇒ x = 61.25

Is this solution Helpfull? Yes | No   

rajat goyal  (10 years ago)

i dun knw. ans to hume na ptaaa

Is this solution Helpfull? Yes | No   

Please Login to Read Solution.