Question

Pipes A and B can fill tank in 5 and 6 hours respectively. Pipe C can empty it in 10 hours.if all the three pipes are opened together, then the tank will be filled in how many hours ?
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Answer 1

Step-by-step explanation:

time taken by a =5

" B = 6

". c= 10

now the total work done by a,b,c = lcm of 5,6,10

= 30

so efficiency of a = 30/5 = 6

" of b = 5

" of c = -3 ( as c empty the tank )

therefore total efficiency = 6+5-3 = 8

so time taken = total work / efficiency

= 30/8