SOLUTION: A bicyclist rides his bicycle 20 miles up a hill and then comes back down. His speed coming downhill is 12 miles per hour faster than going uphill. The round trip takes 2 hours and

Question 1074943: A bicyclist rides his bicycle 20 miles up a hill and then comes back down. His speed coming downhill is 12 miles per hour faster than going uphill. The round trip takes 2 hours and 30 minutes (=5/2 hours). What was the speed of the bicyclist going uphill?
Answer by jorel1380(3719) (Show Source): You can put this solution on YOUR website!
Let n be the speed of the cyclist going up hill. Then his speed downhill would be n+12. So:
20/n + 20/n+12=5/2
40/n + 40/n+12=5
40(n+12)+40n=5n�+60n
5n�-20n-480=0
n�-4n-96=0
(n-12)(n+8)=0
n=12 or -8
The uphill speed of the cyclist was 12 mph. ☺☺☺☺
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