+37155 From 3 miles to 4 is an increase of 2.25 so 2.25 per mile
at 3 miles this charge would be 6.75 but there is a base charge included 8.25 - 6.75 = 1.50
So total charge is 1.50 + 2.25 * miles = you should be able to calculate the total charge for 5 and 6 miles now.....
