Amanda's trip involved an 8-hour drive to her destination and a 5-hour return trip that was 21% faster. The distance for both trips can be expressed in terms of speed and time, but a relationship between the speeds on both trips is necessary to solve for the total distance. Without additional information about the speed on either leg of the journey, the problem remains unsolvable. The discussion highlights the need for clarity on units of measurement to determine the distance traveled accurately. Overall, the problem illustrates the complexities of calculating distance when key variables are missing.