<PRE><B>Question 902086</B>
A roofer and an assistant can repair a roof together in 4 hours. Working alone, the assistant can complete the repair in 13 hours. If both the roofer and the assistant work together for 3 hours and then the assistant is left alone to finish the job, how much longer should the assistant need to finish the repairs? (Round your answer to one decimal place.)
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1/13=work rate of assistant
1/4=work rate for roofer and assistant working together
..
3(1/4)+x/13=1
3/4+x/13=1
x/13=1/4
x=13/4=3.4
how much longer should the assistant need to finish the repairs? 3.4 hrs</PRE>