80 kilometers per hour 90 kilometers per hour 100 kilometers per hour 180 kilometers per hour
John drove a truck for one hour at a rate of 80 kilometers per hour. The next hour, he drove at 100 kilometers per hour. What was his average speed during those two hours?

Options:
- 80 kilometers per hour
- 90 kilometers per hour
- 100 kilometers per hour
- 180 kilometers per hour

90 kilometers per hour