Question

Mario charges $20 an hour plus a $15 flat fee. Luigi charges $18 an hour plus a $30 flat fee. After how many hours will the cost be the same?

Answer 1

7.5 hours

Explanation:

if x is the hours, then

Mario will charge 20x + 15

Luigi will charge 18x + 30

so 20x + 15 = 18x + 30

20x - 18x = 30 - 15

2x = 15

x = 7.5 hours