Question

Valeria has an ambitious goal of biking a 200 kilometer road route in less than 12 hours. The graph below shows the distance she traveled across the 12-hour trip. What was Valeria's average speed during the first 7 hours?During which time period ( F through n show on the graph) was her rate the greatest? how do you know? 

Answer 1

The average speed must be, (x = distance, t= time)

$S=\frac{x2-x1}{t2-t1}=\frac{100\text{ km}}{7\text{ h}}=14.3\text{ km/h}$

The time period in which the speed was greatest was n, because the slope of the line is the highest. She biked approximately 50 Km in one hour, in any of the other time periods she did so.