1. "You look hot," Susan exclaimed, as her husband came in. "Been on the river?" Greg nodded. "I took the canoe for some exercise," he replied. "Paddled downstream for twenty minutes, and then upstream right away for the same time, a good speed all the way. That landed me at the bridge just two miles from here, so I still had to paddle back." What was the speed of the current?

2 miles per hour

3 miles per hour

4 miles per hour