Question

On vacation, Le Hong averaged 45 mph traveling from city A to city B. Returning by a different route that covered the same number of miles, he averaged 50 mph. What is the distance between the two cities if his total traveling time was 30 hours

Answer 1

if the distance is x, then since time is distance/speed,

x/45 + x/50 = 30
x = 710.53 miles

check:
710.53/45 = 15.789 A to B
710.53/50 = 14.211 B to A
total: 30 hours