<PRE><B>Question 1050649</B>
takes the experienced rooster x hours, the other 2x hours
in 1 hour, the experienced roofer does 1/x of the house, the inexperienced 1/2x hours
in 4 hours, the experienced does 4/x and the other 4/2x of the house.
That finishes it, so the two add to 1
(4/x)+(4/2x)=1
multiply everything by 2x
8+4=2x
2x=12
x=6 hours for the experienced one alone  ANSWER
12 hours for the other
together (4/6)+(4/12)=1</PRE>