<PRE><B>Question 1181320</B>
Working together, Adam and Chris can reseal a driveway in
6 hours. 
Together they can reseal 1/6 of the driveway in 1 hour

Working alone, Adam can reseal the driveway in 15
Adam can reseal1/15 of the driveway in 1 hour

Let Chris take x hours to complete the job alone
He does 1/x of the job in 1 hour

1/15 + 1/x = 1/6

1/x = 1/6 -1/15
1/x = 9/90 = 1/10

x= 10

Chris take 10 hours to complete the job alone
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