Answer:
57.1 km/hr
Explanation:
To find the average speed you take the total distance divided by the total elapsed time.
So, the total distance is 140 + 60 = 200
the total elapsed time is found by taking 140/70=2 and 60/40=1.5
2+1.5=3.5
The plug the numbers into the equation,
200/3.5=57.1
