A trucker handed in a ticket at a toll booth showing that in 2 h she had covered 159 mi on a toll road with speed limit 65 mph. The trucker was cited for speeding. Why?

Answer 1

First, the average speed was 159/2= 80 mph.

How could he have ever hand an average of 80 with staying in the limit of 65?

Answer 2

its proven by the mean value theorum f'(c)=f(b)-f(a)/(b-a)