the person covers different distances at different speeds
to find the average speed we have to find the total distance travelled and the total time taken
average speed = total distance travelled / total time taken
first 200 miles
speed - 50 mph
time taken for 50 miles - 1 hour
then time for 200 miles - 1/50 x 200 = 4 hours
last 100 miles
speed - 40 mph
time taken for 40 miles - 1 hour
time for 100 miles - 1/40 x 100 = 2.5 hours
total time taken for a distance of 300 miles - 2.5 + 4 = 6.5 hours
average speed = 300 miles / 6.5 hours = 46.2 mph
average speed is 46.2 mph
