Question

Ying Zyiyu covered the first 300 miles of a trip going at 60 mph and the last hundred going at 40 mph. What was his average speed for the entire trip?

Answer 1

53 1/3 mph

Explanation:

Speed equals distance over time.

She covered 300 miles in 60mph, which took 5 hours.

(300/60=5 )

She also covered 100 miles in 40mph, which means she took 2.5 hours.

(100/40=2.5)

So the total distance is 400miles and the total time is 7.5 hours.

s=d/t substitute values which gives you 400/7.5 which equals 53 1/3 mph

Answer 2

53.3mph (1d.p.)

300mi / 60mph = 5h

100mi/ 40mph = 2h 30min =2.5h

Total time = 7h 30min = 7.5h

Total Distance = 400 mi

400mi / 7.5h = 53.333333mph

Round it off and you get 53.3mph