speed = distance / time
speed = 100 / 11
speed = 9.09m/s
to get rid of meters and get miles you want to multiply by 1 mile then divide by 1609 meters. to get hours, you times the amount of seconds in an hour (3600) and divide by 1 hour
9.09m/s × 1mile / 1609m × 3600s / 1 hour = 20.3 miles / hour