Latest Cognizant Aptitude Question SOLUTION: A water filter takes 40 minutes to filter 20 liters of water Another filter of same specifications takes 30 minutes to filter the same amount of water If both the filters are used

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(#M40156573) COGNIZANT Numerical Ability question Aptitude Keep an EYE

A water filter takes 40 minutes to filter 20 liters of water Another filter of same specifications takes 30 minutes to filter the same amount of water If both the filters are used at the same time, then how long will it take them to filter 70 liters of water?
A) 30 minutes
B) 45 Minutes
C) 60 minutes
D) 90 minutes

Asked In Cognizant B NAGA DHEERAJ (7 years ago)

Unsolved Read Solution (8)

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Read Solution (8) :

Devendra Marghade  (7 years ago)

C) 60 minutes

1 min. capacity of both the filters= (20/40)+(20/30)= 7/6 Liters
So to filter 70 liters, time required= 70/(7/6)= 60 minutes

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ayub   (7 years ago)

40 mins for 20 lit
1 mint = 20/40 = 1/2 lit
again , 1 min for other = 2/3 lit
thus 1/2 +2/3 = 7/6
time required for 70 lit is = 6/7 * 70 = 60 minutes (C)

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PRIYANKAR SANDEL  (7 years ago)

ans is option C...

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Siju Varghese  (5 years ago)

For the first filter,
40 minutes take to fill 20 liters of water.
Therefore,in 1 minute 20/40=1/2 liters of water can be filled.

For the second filter,
30 minutes take to fill 20 liters of water.
Therefore,in 1 minute 20/30=2/3 liters of water can be filled.
So,Two types together can fill in 1 minutes=(1/2+2/3)=7/6 liters.
Now,if 7/6 liters can be filled in 1 minute then,
70 liters can be filled in=(6/7)*70=60 minutes=1 hour.

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Pranjal  (7 years ago)

c)60 litres for 20 litres it takes
(1/40)+(1/30)=70/1200 so work is 1200/70
s0 for 70 litres it will take=(1200/70*1/20*70)=60

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sudha  (6 years ago)

60 dont know

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Debjit Nath  (5 years ago)

C) 60 minutes

1 min. capacity of both the filters= (20/40)+(20/30)= 7/6 Liters
So to filter 70 liters, time required= 70/(7/6)= 60 minutes

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Siva  (4 years ago)

60 minutes

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