Question 1141654
Two mechanics worked on a car.
 The first mechanic worked for 5 hours, and the second mechanic worked for 15 hours.
 Together they charged a total of $1150.
 What was the rate charged per hour by each mechanic if the sum of the two rates was $120 per hour?
:
let a = amt charged by the 1st mechanic (per hr)
let b = amt charged by the 2nd
:
"Two mechanics worked on a car. The first mechanic worked for 5 hours, and the second mechanic worked for 15 hours. Together they charged a total of $1150."
5a + 15b = 1150
" What was the rate charged per hour by each mechanic if the sum of the two rates was $120 per hour? "
a + b = 120
multiply by 5, subtract from the 1st equation
5a + 15b = 1150
5a + 5b = 600
----------------subtraction eliminates a, find b
0 + 10b = 550
b = 550/10
b = $55 per hr, the 2nd mechanic
then
120 - 55 = $65, the 1st mechanic 
;
:
Check, find the total amt each charged
5(65) = $325
15(55)= $825
===============
Total: $1150