SOLUTION: Josie is biking across her state. It takes 23 hours to complete the 213 mile ride. For the first leg, she is pedaling downhill and is averaging a speed of 12 miles an hour. Upon re

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: Josie is biking across her state. It takes 23 hours to complete the 213 mile ride. For the first leg, she is pedaling downhill and is averaging a speed of 12 miles an hour. Upon re      Log On


   



Question 946903: Josie is biking across her state. It takes 23 hours to complete the 213 mile ride. For the first leg, she is pedaling downhill and is averaging a speed of 12 miles an hour. Upon reaching the second leg her speed is cut down to 3 miles an hour. How long did she spend biking downhill?
Answer by josgarithmetic(39620) About Me  (Show Source):
You can put this solution on YOUR website!
First part was downhill, and second part was uphill.
R=12
r=3
T=23 hours, total trip time
D=213 miles, total trip distance

This could be set up in one unknown variable, but it is done here using two unknown variables:
u, the time downhill
v, the time uphill

________________speed___________time____________distance
FIRST___________R________________u______________Ru
SECND___________r________________v______________rv
Total____________________________T_______________D

Fundamentally, rate%2Atime=distance.