Answer:
2.07 miles
Step-by-step explanation:
If Heather runs 3/3 of a lap around course. Steph runs 3/9 of a lap around the race course, the difference in the distance run by Heather and Steph is 3/3 - 3/9 = 1 - 1/3 = 2/3
Since a 5k run race is 3.1 miles, Heather goes 2/3 × 3.1 miles = 6.2/3 miles = 2.07 miles more than Steph.