Fiona Shrek meeting

Fiona sets off from the tower after Shrek at 9:10 at a speed of 6 km/h. Shrek starts to meet her from the swamp at 9:50 at a speed of 4 km/h. At 10:50, they meet and return back to the swamp at a speed of 4 km/h. What time does he arrive at the swamp?

Result

t₃ = 11:50 hh:mm

Step-by-step explanation:

$$\begin{gathered} v_1=6\text{km/h} \\ {v}_2=4\text{km/h} \\ {t}_1=9+50/60=\frac{59}{6}\doteq 9.8333\text{h} \\ {t}_2=10+50/60=\frac{65}{6}\doteq 10.8333\text{h} \\ d=t_2-t_1=10.8333-9.8333=1\text{h} \\ {t}_3=t_2+d=10.8333+1=11.83333=11:50\text{hh}:\text{mm} \end{gathered}$$

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