A car rental Agency advertised renting a car for $23.95 per day and $0.28 per mile. If Greg rents his car for 3 days, how many whole miles can he drive on a $100 budget?

Step 1 ：First, calculate the total cost of renting the car for 3 days. This is done by multiplying the cost per day ($23.95) by the number of days (3). So, \(23.95 \times 3 = 71.85\).

Step 2 ：Next, subtract the total cost of renting the car from the total budget to find out how much money is left for mileage. So, \(100 - 71.85 = 28.15\).

Step 3 ：Finally, divide the remaining budget by the cost per mile to find out how many whole miles Greg can drive. So, \(\frac{28.15}{0.28} = 100.54\). Since Greg can only drive whole miles, we round this down to 100.

Step 4 ：Final Answer: Greg can drive \(\boxed{100}\) whole miles on a $100 budget.