Sadie, Ariana and Sarah are running a relay race. Each part of the race is a different length and covers different terrain. It takes Sadie 2 hours to run through the forest at an average speed of 3 miles per hour. Ariana sprints across the open field on her section at 6 miles per hour for half an hour. If Sarah runs along the beach at four miles per hour and their total time for the race is four and half hours, what is the total distance of the race?
Solve this problem.