A more thorough explanation:

Definition: A ton mile is a unit of measurement used in transportation that represents the movement of one ton of freight over a distance of one mile.

Example: If a truck carries 10 tons of goods for a distance of 50 miles, the total ton miles would be 500 (10 tons x 50 miles).

Explanation: The example shows that the total ton miles is calculated by multiplying the weight of the goods (in tons) by the distance traveled (in miles). In this case, the truck carried 10 tons of goods for a distance of 50 miles, resulting in a total of 500 ton miles.