Four students participate as a team in a 1000 m wacky relay race. In a wacky
relay race, the students each run a portion of the 1000 m length, but they do not
run equal lengths. Andrea and Billie run 1
8
and 1
5
of the total length, respectively.
Carol runs the average of what Andrea and Billie run. Dana runs the remainder
of the length.
Determine the fraction of the total length that Dana runs.