We can setup a simple ratio and solve this problem.
We can say:
2/7 miles to 2/5 hr MEANS how many miles per 1 hour???
Let's call the unknown "x", so we can write the ratio as:
![((2)/(7))/((2)/(5))=(x)/(1)](https://img.qammunity.org/2023/formulas/mathematics/college/5j7xxln656nxq6sh0twnec8rzs33txp3sf.png)
Now, we cross multiply and solve for x:
![\begin{gathered} ((2)/(7))/((2)/(5))=(x)/(1) \\ x\cdot(2)/(5)=1\cdot(2)/(7) \\ (2)/(5)x=(2)/(7) \\ x=((2)/(7))/((2)/(5)) \\ x=(2)/(7)\cdot(5)/(2) \\ x=(5)/(7) \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/1el0wed9u5l1suvbnwfsnqdzcb7amg4wgf.png)
So, unit rate is 5/7 miles per hour.