There are three drains in a 6-metre-deep reservoir of water. To lower the water
level by 2 metres it takes drain A 2 hours, drain B 3 hours, and drain C 4 hours. If
all three drains are opened at once, how long will it take to empty the reservoir?

Question

There are three drains in a 6-metre-deep reservoir of water. To lower the water
level by 2 metres it takes drain A 2 hours, drain B 3 hours, and drain C 4 hours. If
all three drains are opened at once, how long will it take to empty the reservoir?

decentnabeel · Answer

@kropot72  @ParthKohli  @QueenFromADayOfRace

mrcoolguy · Answer

i think A but i'm not sure :(

mrcoolguy · Answer

@umerlodhi

pillowface750 · Answer

im going to say A too...

anonymous · Answer

Drain A does 2 meters/2 hours so 1 meter/hour
Drain B does 2 meters/3 hours so 2/3 meters/hour
Drain C does 2 meters/4 hours so 1/2  meter/hour
So all together, they do 13/6 meters of water in an hour.
6/(13/6)=2.76923077 hours

umerlodhi · Answer

yah so this is very late medal and fan me