Julia left school and travel toward the train station. One hour later Carlos left traveling at 30 mph in an effort to catch up to Julia. After traveling for two hours Carlos finally caught up. Find Julie is average speed

Speed = distance/time

distance = speed * time

Carlos traveled for 2 hours.

Julia traveled for 1 more hour, or 3 hours

Carlos:

time = 2

distance = d

speed = 30 mph

distance = speed * time

d = 30 * 2

d = 60 miles

They both traveled 60 miles.

Julia:

time = 3

distance = 60 miles

speed = s

speed = distance/time = (60 miles) / (3 hours) = 20 mph

Julia's speed is 20 mph.