Final answer:
Using algebra, we find that the first mechanic charges $115 per hour and the second mechanic $100 per hour. None of the given options match this answer.
Step-by-step explanation:
The question asks to solve for the hourly rates of two mechanics given the total amount charged and the sum of their hourly rates. This is a system of equations problem that can be solved using algebraic methods.
Let's denote the rate of the first mechanic as x dollars per hour and the rate of the second mechanic as y dollars per hour. We have two equations based on the information given:
20x + 15y = 3800 (Total charge equation)
x + y = 215 (Sum of rates equation)
To solve this system, you can multiply the second equation by 15 to facilitate the elimination method:
15x + 15y = 3225
20x + 15y = 3800
Subtracting the first equation from the second gives us:
5x = 575
x = 115
Plugging x back into the second original equation:
115 + y = 215
y = 100
Therefore, the first mechanic charges $115 per hour and the second mechanic charges $100 per hour. This means none of the options (a) through (d) given in the question are correct.