Markus jogs 4 mi around a track at an average rate of r mi/h. Then he cools down by walking 1 mi at a rate 3 mi/h slower. His whole workout lasts 1 h. At what rates did Markus jog and walk?

Answer 1

It will do you no good to keep posting the same question every minute or two!

Answer 2

That said, try this:

Since time = distance/speed,

4/r + 1/(r-3) = 1
r = 6