Question

pipe A fill a cistern in 12 hours and pipe B empties it in 15 hours. both pipes are opened in how much time the cistern would filled up​
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Answer 1

Answer:Part filled by (A + B + C) in 3 minutes = 3  1 + 1 + 1  =  3 x 11  = 11 .

30 20 10 60 20

Part filled by C in 3 minutes = 3 .

10

Required ratio =  3 x 20  = 6 .

10 11 11

Step-by-step explanation:

Answer 2

Step-by-step explanation:

A fill a cistern in 12 hours

A one hr work is 1/12

B empties it in 15 hours

B 1hr work is 1/15

both 1hr work = 1/12-1/15

= 5/60 - 4/60

= 1/60

both pipe can fill up the cistern is 60hr

....666...