Answer:
6.5 km per minute
Step-by-step explanation:
To calculate the average speed, you add the speed of one trip to the speed of the other then divide by 2.
The first trip was a speed of 80km/10 minutes or 8km per 1 minute.
The second trip was a speed of 100km/20 minutes or 5km per 1 minute.
To find the average, add and divide by 2:
[tex]\frac{8+5}{2}=\frac{13}{2}=6.5[/tex] km per minute
