Chen rode his skateboard 3 3/4 miles in 3/4 off an hour. What was his average speed in miles per hour?
To find Chen's average speed, we can divide the total distance he traveled by the total time it took him.
Total distance: 3 3/4 miles
Total time: 3/4 hours
Average speed = Total distance / Total time
Average speed = (15/4) / (3/4)
Average speed = (15/4) * (4/3)
Average speed = 15/3
Average speed = 5 miles per hour
Therefore, Chen's average speed was 5 miles per hour.