Bill and Amy want to ride their bikes from their neighborhood to school which is 14.4 km away. It takes Amy 40 mins to arrive at school. Bill arrives 20 mins after Amy. How much faster(in meters/second) is Amy's average speed for the entire trip?
Amy's Speed = 14400m/2400s = 6 m/s.
Bill's Speed = 14400m/3600s = 4 m/s.
So Amy's speed is 2 m/s faster.