Bill and any want to ride their bikes from their neighborhood to school which is 14.4 kilometers away. It takes Amy 40 minutes to arrive at school. Bill arrives 20 minutes after any. How much faster (in meters/second) is amy's average speed for the entire trip?

2 m/s

Explanation:

Given;

Distance from from their neighborhood to school = 14.4 km.

Amy takes 40 minutes,

Bill takes 20 minutes extra than Amy, so Bill takes total 40+20 = 60 minutes;

Hence;

Amy's speed; Km/minute = 14.4/40 = 0.36 km/minute

and in seconds = 360 m/60 seconds = 6 m/sec

Bill's speed; km/minute = 14.4/60 = 0.24 km/minute = 240 m/60 seconds = 4 m/sec

Amy average speed is 2 m/sec faster than Bill.