Question

Kathy bicycles 4 km/hr faster than Carlos. In the same time it takes Carlos to bicycle 27 km, Kathy can bicycle 39 km. How fast does each bicyclist travel?

Answer 1

use
\[t=\frac{d}{r}\] and since the time is the same put \[\frac{27}{r}=\frac{39}{r+4}\]
\[39r=27(r+4)\]
\[39r=27r+156\]
\[12r=156\]
\[r=13\]

Answer 2

carlos at 13, kathy at 17

Answer 3

great thanks