Answer:
12.5 hrs
Explanation:
For auto body charges, the equation will be
cost = 125 + 18 h..............eq 1
For car care charges, the equation will be
cost = 200 +12 h.............eq 2
for the cost to be equal,
From eq 1 and eq 2
125 + 18 h = 200 + 12h
18h - 12h = 200-125
6h = 75
h = 75/6 = 12.5 hrs
12.5 hrs both shops need to work for the prices to be equal