Answer: 400 miles
Explanation:
To find the number of miles in a day at which the rental costs for company A and company B are the same, we can set up an equation to represent the total cost for each company.
Let's say the number of miles driven in a day is represented by x.
For company A, the rental cost per day is $120, and the cost per mile is $0.40. The total cost for company A can be represented as:
Total cost for company A = $120 + ($0.40 * x)
For company B, the rental cost per day is $80, and the cost per mile is $0.50. So the total cost for company B can be represented as:
Total cost for company B = $80 + ($0.50 * x)
To find the number of miles at which the rental costs for both companies are the same, we set up an equation and solve for x:
$120 + ($0.40 * x) = $80 + ($0.50 * x)
Simplifying the equation, we get:
$120 - $80 = ($0.50 * x) - ($0.40 * x)
$40 = $0.10 * x
Dividing both sides of the equation by $0.10, we get:
$40 / $0.10 = x
400 = x
Therefore, the rental costs for company A and company B will be the same when the number of miles driven in a day is 400 miles.