Latest Tech Mahindra Aptitude Question SOLUTION: 1. A, B and C are pipes attached to a cistern. A and B can fill it in 10 and 15 minutes respectively, While C can empty it in 20 minutes. If A, B and C be kept open successively fo

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(#M40034142) TECH MAHINDRA Numerical Ability question Keep an EYE

1. A, B and C are pipes attached to a cistern. A and B can fill it in 10 and 15 minutes respectively, While C can empty it in 20 minutes. If A, B and C be kept open successively for one minute each, find the last integral number of minutes required for the cistern to get filled

Asked In Tech Mahindra m b naga lakshmi (10 years ago)

Solved Devendra Marghade Read Solution (16)

Is this Puzzle helpful?   (42)   (21) Submit Your Solution Time and Work

Read Solution (16) :

Devendra Marghade  (10 years ago)

24 min. 40 sec.
3 min filling=(1/10)+(1/15)-(1/20)=7/60
So upto 3*8=24th min, cistern filled=7*8/60=56/60=14/15
Remaining=1/15, which is to be filled by 'A' again
time taken by A=(1/15)/(1/10)=2/3 min.=40 sec.
So total time required=24 min+ 40 sec.

Is this solution Helpfull? Yes (61) | No (16)  

Sudipta Masanta  (10 years ago)

A fill it in 1 min 1/10
B fill it in 1 min 1/15
C empty in 1 min 1/20
In 1 min it is filled if the 3 pipes are open 1/10+1/15-1/20=7/60
It will be filled in 60/7 min=8.57 min

Is this solution Helpfull? Yes (21) | No (16)  

PARVY GOVIL  (10 years ago)

work in 3 minutes =1/10 + 1/15 -1/20 =7/60
thus 7/60 is filled in 3 mins thus 60/7 *3=26mins 11 sec to fill the tank

Is this solution Helpfull? Yes (11) | No (12)  

monawarul haque  (10 years ago)

A can fill 10% in 1 min, B 6.6% and C can empty 5% in 1 min....altogether 11.6% of work is done in 3 min...so altogether 92.8% work can be done in 24 min and remaining 7.2% work can be done by A in 43 secs....therefore cistern can get filled in 24 min 43 secs.

Is this solution Helpfull? Yes (7) | No (3)  

ravi jha  (10 years ago)

A,B,C successively filled 1 min each(total 3min)=(x/10)+(x/15)-(x/20)=7x/60
After 7*3 min(21min),cistern fill= 49x/60
After 8*3 min(24min),cistern fill= 56x/60
After 9*3 min(27min),cistern fill= 63x/60>1

So its filled between 24 and 27,
Now For 25Th Min, cistern fill= 56x/60+A's filling in 1min=56x/60+x/10=62x/60 >x (So its filled in 25th Min)

So Answer=25min

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

khan  (10 years ago)

25 is the answer

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

ramesh  (9 years ago)

(1/10) +(1/15) -(1/20)=(1/x)
=>in 3 min (7/60)of the cistern is filled
=>1 cistern will need 24min and 40 sec to fill completely

Is this solution Helpfull? Yes (3) | No   

Satyajeet Kumar  (10 years ago)

A does 10% work in 1 minute, B does 6.77% work in 1 minute and C does 5% work in 1 minute(negative work)

now in every 3 minutes % of work done = 10%+6.77%-5%= 11.67%
now as work is taken for 3 minute basis so..total work required= 3*100%
therefore time taken = (3*100%)/11.67%= 25.706
taking only integer part = 25 minutes (answer)

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

Sakshi kochhar  (10 years ago)

(1/10) +(1/15) -(1/20)=(1/x)
=>in 3 min (7/60)of the cistern is filled
=>1 cistern will need 24min and 40 sec to fill completely

Is this solution Helpfull? Yes (2) | No   

Bibek Patnaik  (7 years ago)

Admin please mark the correct answer.....

Is this solution Helpfull? Yes (1) | No   

naveen  (10 years ago)

a=110 b=115 c=120 (for 1 minute)
if all the pipes are allowed to do their respective work(i.e a,b=in c=out)
then,
1/10+1/15-1/20
=>14/120(amount filled in 1 minute)
so,120/4 is the time taken to fill the whole tank
120/4=30 minutes

Is this solution Helpfull? Yes | No (12)  

ravi jha  (10 years ago)

A,B,C successively filled 1 min each(total 3min)=(x/10)+(x/15)-(x/20)=7x/60
After 7*3 min,cistern fill= 49x/60
After 8*3 min,cistern fill= 56x/60
After 9*3 min,cistern fill= 63x/60>1

So its filled between 24

Is this solution Helpfull? Yes | No (3)  

MUKESH KUMAR  (10 years ago)

25 will be the answer !!!

Is this solution Helpfull? Yes | No (4)  

deepa gudivada  (10 years ago)

1/10+1/15-1/20=7/60
1/60/7=8.6

Is this solution Helpfull? Yes | No (3)  

deepa gudivada  (10 years ago)

1/10+1/15-1/20=7/60
1/60/7=8.6

Is this solution Helpfull? Yes | No (3)  

seshi  (7 years ago)

X O I F ?
a) D b) E c) F d) B
asked in TECHMAHINDRA

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