Pipe & Cisterns

Fast trick to solve the pipe and cisterns.

55 pumps can empty a reservoir in 12 days ,working 8 hours a day. if 220 pumps are used for 3 hours a day then in how many days will the same work be completed?

STEP 1 :

First of all lets calculate the total work for '55' pupms = 55 * 12 * 8

STEP 2 :

Let the reqiured number of days for '220' pumps be x

Now calculate the total work for '220' pumps = 220 * x * 3

STEP 3 :

Now equate the total work for '55' days to work for '220' days

55 * 12 * 8 = 220 * x * 3

55 * 12 * 8 * (1 / 220 * 3) = x

8 = x

Work will be completed in 8 days.