A person drove 65 miles per hour on a trip. If he had driven 78 miles per hour, he would have arrived 4 hours earlier. What was the distance the person drove?

Answer 1

Hi, Jane.

Okay, so we know that distance = rate x time

So the distance he drove was 65t. We also know that it would have been the same distance if he had

driven four hours less at 78 mph.....So that would be 78(t-4)

Therefore,

65t = 78(t - 4)

65t = 78t - 312

13t = 312

t = 312/13 = 24 hours

So, the distance he drove is rate x time = 65mph x 24hr = 1560 miles.