Two mechanics worked on a car. The first mechanic charged $65 per hour, and the second mechanic charged $115 per hour. The mechanics worked for a combined total of 35 hours, and together they charged a total of $3025. How long did each mechanic work?
Let first mechanic's hours be F, and second's, S
Then we get: F + S = 35_____F = 35 - S ------- eq (i)
Also, 65F + 115S = 3,025_____5(13F + 23S) = 5(605)______13F + 23S = 605 ------ eq (ii)
13(35 - S) + 23S = 605 ------- Substituting 35 - S for F in eq (ii)
13(35) - 13S + 23S = 605
10S = 605 - 13(35)
S, or hours worked by the second mechanic =
Substitute 15 for S in eq (i) to get F, the hours worked by the first mechanic