SOLUTION: Dan drove from his farm to town, traveling the first 50 km at 80 km/h, and the next 30 km at 60 km/h. He then returned home at 100 km/h. What was his average speed for the whole tr

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Question 1191596: Dan drove from his farm to town, traveling the first 50 km at 80 km/h, and the next 30 km at 60 km/h. He then returned home at 100 km/h. What was his average speed for the whole trip?
Found 2 solutions by greenestamps, ikleyn:
Answer by greenestamps(13200) About Me  (Show Source):
You can put this solution on YOUR website!


average speed = total distance divided by total time

50km at 80 km/h = 5/8 hours
30km at 60 km/h = 1/2 hour
80km at 100km/h = 4/5 hours

total distance: 160km
total time: (5/8+1/2+4/5) hours

160%2F%285%2F8%2B1%2F2%2B4%2F5%29

you can do the calculations....

Answer by ikleyn(52781) About Me  (Show Source):
You can put this solution on YOUR website!
.

The correct formula to use is 

    160%2F%285%2F8%2B1%2F2%2B4%2F5%29  kilometers per hour.