Question 475054
6 hours to hike up the 12 mile mountain trail and back down. 
rate coming down was twice as fast as rate going up.
 What was the rate going up the mountain?
:
r = going up rate
then
2r = rate coming down
:
Write a time equation; time = dist/rate
:
Up time + down time = 6 hr
{{{12/r}}} + {{{12/(2r)}}} = 6
mult eq by 2r, results
2(12) + 12 = 2r(6)
24 + 12 = 12r
36 = 12r
r = {{{36/12}}}
r = 3 mph rate going up
:
:
Check solution by finding the actual times
12/3 = 4 hrs
12/6 = 2 hrs
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total: 6 hrs