Answer:
The rate per hour of the 1st mechanic is US$ 115, and the rate of the 2nd mechanic is US$ 120.
Explanation:
1. Let's review all the information given to answer the question correctly.
Time of the 1st mechanic working on the car = 20 hours
Time of the 2nd mechanic working on the car = 5 hours
Total rate of the work done by the two mechanics = US$ 2,900
2. What was the rate charged per hour by each mechanic if the sum of the two rates was 235 per hour?
Rate per hour of the 1st mechanic = x
Rate per hour of the 1st mechanic = 235 - x
For solving the value of x, we will use the following equation:
x * 20 + 5 * (235 - x) = 2,900
20x + 1,175 - 5x = 2,900
15x = 2,900 - 1,175 (Like terms)
15x = 1,725
x = 115 (Dividing by 15 at both sides)
The rate per hour of the 1st mechanic is US$ 115, therefore the rate of the 2nd mechanic is US$ 120 (235 - 115).
Total charged by the 2 mechanics = 115 * 20 + 120 * 5
Total charged by the 2 mechanics = 2,300 + 600
Total charged by the 2 mechanics = 2,900