Alright, lets get started.
Suppose first mechanic charges= x
So, second mechanic charges will be = (because total of their rates was 125)
first mechanic worked for 5 hours, and the second mechanic worked for 15 hours and together they charged a total of $1225
Means
Adding 10 x in both sides
Subtracting 1225 from both sides
Dividing 10 in both sides
x = 65
For second mecahnics rate = 125 - 65 = 60
Hence The mechanic who worked 5 hours charged $ 65 per hour, the one who worked 15 hours charged $ 60 per hour: Answer
Hope it will help :)