Respuesta :

The answer is 6.5km a minute

Why? I made proportions. 80km/10mins and 100km/20mins and then simplified to 8km/1 min and 5km/1min and then I found the average by adding 8+5 (making 13) and then dividing 13 by 2 which would be 6.5. 6.5km a minute.