What was the rate charged per hour by each mechanic if the sum of the two rates was $200 per hour?

Question

Two mechanics worked on a car. The first mechanic worked for 20  hours, and the second mechanic worked for 5  hours. Together they charged a total of $2275

. What was the rate charged per hour by each mechanic if the sum of the two rates was $200  per hour?

Answer 1

20F + 5S = 2275

F+S = 200

S = 200-F

20F + 5(200-F) = 2275

20F-5F = 2275 -5(200)

15F = 2275-1000 = 1275

F = 1275/15 = $85 per hour for the First Mechanic

S = 200-85 = $115 per hour for the Second Mechanic

20(85)+5(115) = 1700+575 = 2275