Question 838495: Chau drove to the mountains last weekend. There was heavy traffic on the way there, and the trip took 12 hours. When Chau drove home, there was no traffic and the trip only took 8 hours. If his average rate was 20 miles per hour faster on the trip home, how far away does Chau live from the mountains?
Answer by ankor@dixie-net.com(22740)   (Show Source):
You can put this solution on YOUR website! Chau drove to the mountains last weekend.
There was heavy traffic on the way there, and the trip took 12 hours.
When Chau drove home, there was no traffic and the trip only took 8 hours.
If his average rate was 20 miles per hour faster on the trip home,
how far away does Chau live from the mountains?
:
Let s = his speed to the mountains
then
(s+20) = his return speed
:
The dist each way is the same, write a dist equation; dist = speed * time
12s = 8(s+20)
12s = 8s + 160
12s - 8s = 160
4s = 160
s = 160/4
s = 40 mph his to the mts speed
then
40 * 12 = 480 mi to the mts
:
:
Check this on the return trip
(40+20) * 8 = 480 mi
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