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?

53.33mph

Step-by-step explanation:

Let's calculated the total time spent on the journey first;

For the first 300miles the time spent is;

From Distance = speed * time

time = Distance / speed

= 300/60 = 5 hours

Similarly for the last 100mile the time taken is;

100/40 = 2.5 hours

Total time spent = 5 + 2.5 = 7.5 hours

Total distance covered 400miles

Therefore average speed = 400/7.5 = 53.33mph