Select all the rates that are unit rates.

1. [tex]\frac{1}{1/3}[/tex]

2.[tex]\frac{2/3}{1}[/tex]

3. [tex]\frac{2}{3}[/tex]

4. [tex]\frac{3}{1}[/tex]

5. [tex]\frac{1}{9}[/tex]

Please help me im confused on what I do here..