Question

answer ==================

Answer 1

Hi friend,

In one hour :
Tank Filled by A = 1/10
Tank Filled by B = 1/12
Tank Empty be C = 1/20

If three pipes are combined then tank filled in one hour = 
1/10 + 1/12 - 1/20
= 2/15
2/15 of tanked filled in one hour.
So time taken to fill tank = 15/2 * 1
= 7.5 hours

Hope this helps!

Answer 2

hope it help u...
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