Question 49196
Start by letting x = the maximum number of miles.
From the problem description, you can write:
$19.50 + $0.18(x) = $33.00
Because the company will reimburse $33.00 which includes the $19.50 per day plus the $0.18 for every mile (x) driven on that day. Solve the above equation for x.

19.5 + 0.18x = 33 Subtract 19.5 from both sides of the equation.
0.18x = 13.5 Divide both sides by 0.18
x = 75

If Mrs. Denney drives 75 miles in one day, the company will reimburse her the total cost of renting the car for that day.

P.S. The fact that the car gets 35 miles to the gallon is interesting but not required to solve this problem.