Question 30847
work is the product of the rate and time
RATE:
the pipe can fill the pool in 10 hours *has to be in fraction, so it is a ratio of 1/10*
the drainer can drain the pool in 16 hours *has to be in fraction, so it is a ratio of -1/16*
TIME:we have to find the time; let us define time as 't'
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RATE*TIME=WORK
pipe = t/10
drainer = -t/16
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it takes one job, so:
t/10 - t/16 = 1
(t/10 - t/16 = 1)80 multiply by lowest common multiple
8t - 5t = 80
3t = 80
t = 80/3
t = 26 and 2/3 hours to fill the pool