So the first thing you can do is find out the amount charged without the initial fee.
41 - 8 = 33
Since they are charging $3 for each half of a mile, to find out how many half miles they drove, you have to divide 33 by 3, which means they drove 11 half miles.
Now, convert that into actual miles.
11 × 0.5 = 5.5
They drove 5.5 miles.
