[tex] 2 \dfrac{1}{2} \text{ hours} \longrightarrow 21 \dfrac{3}{4} \text{ meters}[/tex]
[tex]1 \text{ hours} \longrightarrow 21 \dfrac{3}{4} \div 2 \dfrac{1}{2} \text{ meters}[/tex]
[tex]1 \text{ hours} \longrightarrow \dfrac{87}{4} \times \dfrac{2}{5} \text{ meters}[/tex]
[tex]1 \text{ hours} \longrightarrow \dfrac{87}{10} \text{ meters}[/tex]
[tex]1 \text{ hours} \longrightarrow 8\dfrac{7}{10} \text{ meters}[/tex]
Answer: The unit rate is 8 7/10 meters/hour