### Home > PC3 > Chapter 3 > Lesson 3.1.4 > Problem3-61

3-61.

The Monsters are going to visit relatives. They drive over many kinds of terrain ranging from the highway to gravel roads. They are able to drive $40$ mph for $2$ hours, $60$ mph for another hour, and only $20$ mph for the final $30$ minutes of the trip. What was their average speed for the entire $3.5$-hour trip?

First calculate the total distance the Monsters traveled.
Then determine the average speed using: $\text{average speed} =\frac{\text{total distance}}{\text{total time}}$