Say the apprentice earns x dollars an hour, and the plumber earns x+15 dollars per hour. Write the equation:
40(x+x+15)=2200
Dividing by 40, we see that:
2x+15=55
Subtracting 15, we see that 2x=40, so x=20. As a result, the apprentice earns $20 an hour, and the plumber earns #35 per hour.
