Question 745393: jan hiked up a hill at 4 mi/hr and back down at 6 mi/hr. Her total hiking time was 3 hours. how long did the trip up the hill take her? Found 2 solutions by josgarithmetic, Alan3354:Answer by josgarithmetic(39625) (Show Source):
You can put this solution on YOUR website! Distance up and distance down are same.
r*t=d, t=d/r
Up hill: 4*x=d
Down hill: 6*y=d
4x=6y
x+y=3 hours.
The description yields the system: and
Just solve this system for x and y.
x is how much time up the hill.
You can put this solution on YOUR website! jan hiked up a hill at 4 mi/hr and back down at 6 mi/hr. Her total hiking time was 3 hours. how long did the trip up the hill take her?
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Avg speed of a round trip is similar to parallel resistances and parallel flows.
Avg = 2*r1*r2/(r1 + r2)
The distance is irrelevant.
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Avg = 2*4*6/(4+6) = 48/10
Avg = 4.8 mi/hr
RT distance = 4.8*3 = 14.4 miles --> 7.2 miles each way
time going uphill = 7.2/4 = 1.8 hours
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