<PRE><B>Question 1081573</B>
 Ben paints a house in 30 hours and Amy paints one in 82.5 hours.
 How long does it take to paint the house together?
:
let t = time required when working together
let the competed job = 1
{{{t/30}}} + {{{t/82.5}}} = 1
multiply equation by 330, cancel the denominators
11t + 4t = 330
15t = 330
t = 330/15
t = 22 hrs working together
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