Two mechanics were working on your car. One can complete the given job in six hours, but the new guy takes 7 hours. They worked together for the first two hours, but then the first guy left to help another mechanic on a different job. How long will it take the new guy to finish your car? Choose the correct choice from the following answers.
A) 7/4	B) 4/3	C) 15/4	D) 10/3	E) 64/21
Rate(1)=1/6   Rate(2)=1/7   Combined = 13/42   Work done in 2 days=13/21   Work left = 8/21   Rate * Time = Work left   1/8 * Time = 8/21   Time=64/21   64/21
<result>E</result>
Two mechanics were working on your car. One can complete the given job in six hours, but the new guy takes 7 hours. They worked together for the first two hours, but then the first guy left to help another mechanic on a different job. How long will it take the new guy to finish your car?