Answer:
[tex]unit \: rate = \frac{distance}{time} \\ [/tex]
substitute:
[tex]unit \: rate = \frac{( \frac{1}{3} ) }{( \frac{1}{9}) } \\ \\ = \frac{1}{3} \div \frac{1}{9} \\ \\ = \frac{1}{3} \times 9 \\ \\ = { \underline{ \: \: 3 \: miles \: per \: hour \: \: }}[/tex]
