SOLUTION: A student walks and jogs to college each day. She averages 5km/h walking and 9km/h jogging. The distance from home to college is 8km, she makes the trip in 1 hour. How far does the

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: A student walks and jogs to college each day. She averages 5km/h walking and 9km/h jogging. The distance from home to college is 8km, she makes the trip in 1 hour. How far does the      Log On


   

Question 247171: A student walks and jogs to college each day. She averages 5km/h walking and 9km/h jogging. The distance from home to college is 8km, she makes the trip in 1 hour. How far does the student jog?
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
averages 5km/h walking and 9km/h jogging.
The distance from home to college is 8km, she makes the trip in 1 hour.
How far does the student jog?
:
Let x = jogging dist
then
(8-x) = walking dist
:
Write a time equation: time = dist/speed
:
jog time + walk time = 1 hr
x%2F9 + %288-x%29%2F5 = 1
Multiply by 45, results:
5x + 9(8-x) = 45
5x - 72 - 9x = 45
5x - 9x = 45 - 72
-4x = -27
x = %28-27%29%2F%28-4%29
x = +6.75 km jogging
:
:
Check solution
8 - 6.75 = 1.25 km walking
Walk time = 1.25/5 = .25 hr
Jog time = 6.75/9 = .75 hr
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total time for both = 1 hr