So the formula for distance is:
[tex]Distance= {Rate}*{Time}[/tex]
So we compute for the distance he traveled by walking and we get:
[tex]5* \frac{4}{3} = \frac{20}{3} [/tex]
(if you are wondering how we got 4/3 we are expressing 1 hour and 20 minutes as 4/3 an hour)
Computing for the distance he traveled before his motorcycle broke down is\
[tex]30- \frac{20}{3} = \frac{70}{3}[/tex]
Therefore he had traveled [tex] \frac{70}{3} [/tex]km before his motorcycle broke down