Answer:
70 mph
Step-by-step explanation:
Here we want to calculate average speed
Mathematically, average speed = Total distance/Total time
Kindly recall distance = speed * time
for the first part;
We have: 60 * 2 = 120 miles
For the second: 4 * 75 = 300 miles
Average speed = (300 + 120)/(4 + 2) = 420/6 = 70 mph