Bicyclist Meeting Walker

At 8:00, Peter set out on a hike at 5 km/h. At 9:12, Michael followed him on a bike at a speed of 20 km/h. At what time did Michael Petra run, and how many kilometers did he cover?

Result

t = 9:36 hh:mm
s =  8 km

Step-by-step explanation:

$$\begin{gathered} 5\cdot (x-8.00)=20\cdot (x-(9.00+12/60)) \\ 900x=8640 \\ x=\frac{8640}{900}=9.6 \\ x=\frac{48}{5}=9.6 \\ t=x=9.6=9:36\text{hh}:\text{mm} \end{gathered}$$

$s=5\cdot (x-8.00)=5\cdot (9.6-8.00)=8\text{km}$

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