Tammy drove to the mountains last weekend. There was heavy traffic on the way there, and the trip took 7 hours. When Tammy drove home, there was no traffic and the trip only took 5 hours. If her average rate was 18 miles per hour faster on the trip home, how far away does Tammy live from the mountains?

Question

anonymous · Answer

Let x be the Tammy's speed driving towards the mountains.
speed times time is equal to distance or r t = d.
Solve the following for x, the average speed to the mountains:$$8 x=5 (x+18) $$  x = 30 mph
8x = 240 miles