Asked by Jay

Stephanie can clean a pool in 1 hour , and Mark can clean the same pool in 1.5 hours. If the rate at which they work together is the sum of their rates working separately, how many minutes should they need to clean the pool if they work together? (1 hr=60 min)

Answers

Answered by Marth
Stephanie cleans at the rate of 1 pools/hr.

Mark cleans at the rate of 1/1.5, or 2/3 pools/hr.

Their combined rate is 5/3 pools/hr

If r is the rate, t is time, and p is the number of pools, then

r = p/t
(5/3pools/hr) = (1 pool)/t
t = 3/5hr
t = 60*3/5 = 36min


Answered by Henry
T = t1*t2/(t1+t2) = 1*1.5/(1+1.5) = 0.6h. = 36 Min.


Answered by Steven
36 is the correct answer.

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