<u>Answer:</u>
First mechanic worked for 20 hours and second mechanic worked for 15 hours.
<u>Solution:</u>
Given, Two mechanics worked on a car.
The first mechanic charged $45 per hour, and the second mechanic charged $120 per hour.
The mechanics worked for a combined total of 35 hours, and together they charged a total of $2700.
We have to find how long did each mechanic work.
Let the time worked by 1st mechanic be t hours then time taken by 2nd mechanic will be 35 – t hours.
Now, according to given information,
45 x t + 120 (35 – t) = 2700
45t + 120 35 – 120t = 2700
-75t + 4200 = 2700
75t = 4200 – 2700
75t = 1500
t = 20
hence, 1st mechanic worked for 20 hours and 2nd mechanic worked for 35 – 20 = 15 hours.