SOLUTION: Tina can run 12 mi in the same time it takes her to bicycle 72 mi. If her bicycling rate is 20 mi/h faster than her running rate, find each rate.

Algebra ->  Expressions-with-variables -> SOLUTION: Tina can run 12 mi in the same time it takes her to bicycle 72 mi. If her bicycling rate is 20 mi/h faster than her running rate, find each rate.       Log On


   

Question 107449: Tina can run 12 mi in the same time it takes her to bicycle
72 mi. If her bicycling rate is 20 mi/h faster than her running rate, find each
rate.
Answer by scott8148(6628) About Me  (Show Source):
You can put this solution on YOUR website!
let x=running, so x+20=bicycling ... t=d/r ... 12/x=72/(x+20)

"cross" multiplying gives 12(x+20)=72x