Answer:
average speed of the person is 3 feet/s
Explanation:
As we know that the average speed of the person is ratio of total distance and total time interval
so here we know that total distance moved by the person is given as
[tex]d = 30 + 10 + 20[/tex]
[tex]d = 60 feet[/tex]
so we have
[tex]t = 20 s[/tex]
so here we have
[tex]v = \frac{d}{t}[/tex]
[tex]v = \frac{60}{20}[/tex]
[tex]v = 3 feet/s[/tex]