Answer: 1/14 of a mile
================================================
Step-by-step explanation:
T = total distance = 1/2 of a mile
x = distance each runner travels = unknown
n = number of runners = 7
T = x*n
1/2 = x*7
1/2 = 7x
7x = 1/2
(1/7)*7x = (1/7)*(1/2) ... multiply both sides by 1/7
x = (1/7)*(1/2)
x = (1*1)/(7*2)
x = 1/14 of a mile
-----------
side note:
5280 feet = 1 mile
5280/14 feet = 1/14 mile ... divide both sides by 14
377.142857 feet = 1/14 mile, approximately