Let's forget for the tie being the cost ($3.5)of the 1st fifth of a mile:
Taxi charge excluding $3.5, is $13.95 - $3.5 = $10.45.
If each of the 5th (1/5) of a mile costs $0.55, then with $10.45 we can drive:
10.45/0.55 = 19 fifth of a mile. Add to that the 1st fifth = 20 fifth of a mile
20 fifth = 20 x 1/5 = 4 miles (answer)
