Answer:
9 hours
Step-by-step explanation:
Let for x hours the amount charged by Abe and Gabe is same.
Given,
In fixing by Abe,
Fixed cost = $ 130,
Additional cost per hour = $ 70,
So, the total charge for x hours = 130 + 70x
In fixing by Gabe,
Fixed cost = $ 40,
Additional cost per hour = $ 80,
So, the total charge for x hours = 40 + 80x
For same charge,
130 + 70x = 40 + 80x
70x = 40 + 80x - 130
70x - 80x = -90
-10x = -90
⇒ x = 9
Hence, it will take 9 hours for both Abe and Gabe to cost the same amount