Margaret drove 30 miles one way and 30 miles back, totaling 60 miles.
Given that Margaret drove to a business appointment at 30 mph, and her average speed on the return trip was 20 mph, and the return trip took 1/2 hr longer because of heavy traffic, to determine how far did she travel to the appointment the following calculation must be performed:
30 - 20 = 10
10 = 0.5 hours = 30 minutes
30 = 1
20 = 0.666
1 = 1
1.333 = 1.5
1 = 30 x 2 = 60
Therefore, Margaret drove 30 miles one way and 30 miles back, totaling 60 miles.