Question

Bob drove to the mountains last weekend. There was heavy traffic on the way there, and the trip took 8 hours. When Bob drove home, there was no traffic and the trip only took 5 hours. If his average rate was 21 miles per hour faster on the trip home, how far away does Bob live from the mountains? Do not do any rounding.

Answer 1

Answer:280 miles

let x=rate of speed on the way to mountains

x+21=rate of speed on the way home

travel time*rate=distance

8x=5(x+21)

8x=5x+105

3x=105

x=35

8x=280

how far away does Bob live from the mountains? =280 miles