Consider the relation,
Let the distance between Trent and Austin is 'd' kilometers.
Then the time taken by Trent to reach Austin is given by,
Similarly, the time taken by Trent on his return trip is given by,
Given that the trip to Austin was 1 hour less than the return trip,
Solve for the total time of the trip as,
Thus, the total time required for complete trip is 5 hours.