SOLUTION: A family makes a 43.25 km trip in 5.5 hours. On the first part of the trip they crossed a lake in a canoe paddling at 12km/h. For the rest of the trip,they hiked on a scenic trail.

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Question 159534: A family makes a 43.25 km trip in 5.5 hours. On the first part of the trip they crossed a lake in a canoe paddling at 12km/h. For the rest of the trip,they hiked on a scenic trail. If their average walking speed was 5km/h how far did they walk?
Answer by jojo14344(1513) About Me  (Show Source):
You can put this solution on YOUR website!

Remember: Speed=distance%2Ftime ---> S=d%2Ft, BASIC EQN
S%5B1%5D=12km%2Fhr, canoe paddling
S%5B2%5D=5km%2Fhr, hike in scenic trail (walking)
Other points to remember: distance=d=43.25km, t=5.5hrs
In BASIC EQN we get, t=d%2FS, working eqn
Also, t%5B1%5D%2Bt%5B2%5D=t. Make sense, time in canoe paddling + time hiking = total time in the trip.
Then as per working eqn,
d%5B1%5D%2FS%5B1%5D%2Bd%5B2%5D%2FS%5B2%5D=5.5hrs ----------------> eqn 1
But remember too, d%5B1%5D%2Bd%5B2%5D=43.25km distance in canoe paddling + distance in hiking = total distance in trip ---> d%5B1%5D=43.25-d%5B2%5D,subst, in eqn 1
43.25-d%5B2%5D%2F12%2Bd%5B2%5D%2F5=5.5
5%2843.25-d%5B2%5D%2B12d%5B2%5D%29%2F60=5.5
%28216.25-5d%5B2%5D%2B12d%5B2%5D%29%2F60=5.5, cross multiply
12d%5B2%5D-5d%5B2%5D=330-216.25
7d%5B2%5D=113.75
cross%287%29d%5B2%5D%2Fcross%287%29=cross%28113.75%2916.25%2Fcross%287%29
d%5B2%5D=16.25km --------------------> distance travelled in walking
d%5B1%5D=43.25-16.25=27km -----------> distance travelled in canoe paddling
In doubt? Go back eqn 1,

2.25hrs%2B3.25hrs=5.5hrs
5.5hrs=5.5hrs
Thank you,
Jojo