Respuesta :
30 minutes is 1/2 of an hour.
So if you just multiplied 21×2, you would get you answer.
The answer is:
42 kilometers per hour
So if you just multiplied 21×2, you would get you answer.
The answer is:
42 kilometers per hour
Average speed = (distance covered) / (time to cover the distance)
Average speed = (21 km) / (1/2 hour)
Average speed = (21/0.5) (km/hour)
Average speed = 42 km/hr
A very slow airplane ! Maybe an ultralight, a motorized hang-glider, etc.