Question 792983
Suppose you hike up a hill at 4 km/h. You hike back down at 6 km/h.
 Hiking trip took 3 hours.
How much time did it take you to hike up the hill?
:
Let d = the one-way distance
Write a time equation; time = dist/speed
:
Time up + time down = 3 hrs
{{{d/4}}} + {{{d/6}}} = 3 
multiply by 12, results:
3d + 2d = 12(3)
5d = 36
d = 36/5
d = 7.2 km
Find the time up the hill
7.2/4 = 1.8 hr up the hill
:
Check this by finding the time down the hill
7.2/6 = 1.2 hrs
1.8+1.2 = 3 hrs