Average speed

The average speed of a pedestrian who walked 10 km was 5km/h, and the average speed of a cyclist on the same track was 20km/h. In how many minutes did the route take more than a cyclist? Q

Correct answer:

x =  90 min

Step-by-step explanation:

$$\begin{gathered} s=10\text{km} \\ {v}_1=5\text{km/h} \\ {v}_2=20\text{km/h} \\ t=t_1-t_2 \\ {t}_1=s/v_1=10/5=2\text{h} \\ {t}_2=s/v_2=10/20=\frac{1}{2}=0.5\text{h} \\ t=t_1-t_2=2-0.5=\frac{3}{2}=1.5\text{h} \\ x=t\to \text{min}=t\cdot 60\text{min}=1.5\cdot 60\text{min}=90\text{min}=90\text{min} \end{gathered}$$

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