Question

A tap A can fill a drum in 10 minutes.A second tap B can fill in 20 minutes.A third tap C can empty in 15 minutes. If initially the drum is empty,find when it will be full if all taps are opened together?

Answer 1

the first tap it can fill 1/10 of the tank in 1 minute
the second tap can fill 1/20 of the tank in 1 minute
the third tap can empty 1/15 of the tank in 1 minute .
When all the taps are opened together .Hence , it can fill the tap in 1 minute is = 1/10 + 1/20/ - 1/15
= 1/ 12
Therefore the tank is filled in 12minutes

Answer 2

Step-by-step explanation:

A Can fill a drum in 1/10

B Can fill a drum in 1/20

C can fill a drum in 1/15

1/10+1/20-1/15

Then LCM

6 + 3 - 4 /60

9-4/60

5/60

1/12

then 12minutes