Aaron and Beth combined ran 40% of the total distance.
A + B = 12 miles
Beth and Candace combined ran 34% of the total distance.
B + C = 10.2 miles
Candace and John combined ran 40% of the total distance.
C + J = 12 miles
John and Pat combined ran 41% of the total distance.
J + P = 12.3 miles
A + B + C + J + P = 30
A + (10.2-C) + C + J + (12.3-J) = 30
A + 10.2 + 12.3 = 30
A = 7.5 miles
B = 12 - 7.5 = 4.5 miles
C = 10.2 - 4.5 = 5.7 miles
J = 12 - 5.7 ] = 6.3 miles
P = 12.3 - 6.3 = 6 miles