Answer: 3 hours
Explanation:
Hi, Derrick’s cost is equal to its fixed cost (12) plus the price per hour (5) multiplied by the number of hours (h). Same process for Darlene’s cost.
Derrick's Dog Sitting cost = 12 + 5 h
Darlene's Dog sitting cost = 18 + 3h
If both costs are equal
Derrick's Dog Sitting cost = Darlene's Dog sitting cost
So:
12 + 5 h = 18 + 3h
Solving for h:
5h-3h =18-12
2h = 6
h = 6/2
h=3
The number of hours for which the total cost will be the same for the two services is 3.