Question

Two trucks leave a warehouse at the same time. One travels due south at an average speed of 48 miles per hour, and the other travels due north at an average speed

of 64 miles per hour. After how many hours will the two trucks be 672 miles apart?

Answer 1

6 hours

Explanation:

Since the trucks are moving in exactly opposite directions, the relative speed is 48 + 64 = 112 mph

If they have to be 672 miles apart, then the time taken is 672/112 = 6 hours

Check
After 6 hours, the truck traveling south would have covered 48 * 6 = 288 miles south

The truck traveling north would have covered 64 * 6 = 384 miles north

The distance between them after 6 hours would be 288 + 384 = 672 miles