Final answer:
Alonzo drove approximately 255.74 miles.
Step-by-step explanation:
To find the number of miles Alonzo drove the truck, we can subtract the base fee from the total amount he paid and then divide by the additional charge per mile.
Total cost - base fee = additional charge per mile * number of miles driven
215.11 - 17.99 = 0.77 * number of miles driven
197.12 = 0.77 * number of miles driven
number of miles driven = 197.12 / 0.77
number of miles driven ≈ 255.74 miles