SOLUTION: Joy can run an average speed of 1km every 5 minutes. Walking, she averages 1km every 12 minutes. A. After running for 45 minutes, she decided to walk the next 15 minutes. How fa

Algebra ->  Expressions-with-variables -> SOLUTION: Joy can run an average speed of 1km every 5 minutes. Walking, she averages 1km every 12 minutes. A. After running for 45 minutes, she decided to walk the next 15 minutes. How fa      Log On


   

Question 389792: Joy can run an average speed of 1km every 5 minutes. Walking, she averages 1km every 12 minutes.
A. After running for 45 minutes, she decided to walk the next 15 minutes. How far was she from her starting point?
B. If Joy ran for R minutes and walked for W minutes and arrived at Lake Michigan 14 miles from her starting point,write and equation using R and W to express this situation. 1km=0.62 miles and 1 mile=1.61km
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
Joy can run an average speed of 1km every 5 minutes. Walking, she averages 1km
every 12 minutes.
A. After running for 45 minutes, she decided to walk the next 15 minutes.
How far was she from her starting point?
:
45*1%2F5 + 15*1%2F12 = 10.25 km
:
:
B. If Joy ran for R minutes and walked for W minutes and arrived at Lake Michigan 14 miles from her starting point, write and equation using R and W to express this situation.
:
1%2F5R + 1%2F12W = 1.61(14)
:
1%2F5R + 1%2F12W = 22.54
:
Multiply by 60 to clear the denominators
12R + 5W = 60*22.54
:
5W = -12R + 1352.4
:
Divide by 5
W = -2.4R + 270.48 is the equation
:
If you enter a value for R (running time), this equation will give you W, the walking time, to travel 14 mi (22.54 km)