find the rate of change of bicycling 3 mi in 15 minutes and 7 mi in 55 minutesl

Question

i need to find the rate of change for this, but I don't remember how.

Answer 1

3 miles in 15 minutes is 12mph (15 mins is quarter of an hour). 7 miles in 55 minutes is 7.636mph (slower). The rate in m/min is 0.2 and 0.127. These rates are average speeds. What we don't know is the decelaration rate, which is the change of speed over a period of time.