Given,
The graph of the function m(t) and e(t) is shown in the question.
a)From graph it is clearly seen that,
The distance covered by michael in 20 seconds is 50 feet.
The distance covered by elizabeth in 20 seconds is (60-25)= 35 feet.
b)The speed of Michael is,
The speed of elizabeth is,
Hence, the speed of michael is 2.5 ft/second and elizabeth is 1.75 ft/second.