Question 161321
Kwan hiked uphill at 4km/h and back down at 6km/h. His total hiking time was 3h. how long did the trip up the hill take him?
:
Let t = time to hike up the hill
It states that the total time time up & down is 3 hr; therefore
(3-t) = time down the hill
:
The distance up and down is the same. Write a distance equation from this fact:
Dist = speed * time
:
4t = 6(3-t)
:
4t = 18 - 6t
:
4t + 6t = 18
:
10t = 18
t = {{{18/10}}}
t = 1.8 hrs to hike up the hill. 1 hr 48 min (.8*60)
:
:
Check solution:  Down hill: 3 - 1.8 = 1.2 hrs
6*1.2 = 7.2 mi
4*1.8 = 7.2 mi