Question

Mary drove to the mountains last weekend. There was heavy traffic on the way there, and the trip took 8 hours. When Mary drove home, there was no traffic and the trip only took 6 hours. If her average rate was 16 miles per hour faster on the trip home, how far away does Mary live from the mountains?
Do not do any rounding.

Answer 1

Speed = Distance ÷ time 
Distance ÷ 6  - Distance ÷ 8  = 16
(8D - 6D) ÷ 48 = 16
2D = 16 x 48
2D = 768
D = 384 miles