To find the unit rate price per ounce of the root beer, you can divide the total cost by the number of ounces in the bottle.
Total cost = $3.20
Total ounces = 64 oz
Unit rate price per ounce = Total cost / Total ounces
Unit rate price per ounce = $3.20 / 64 oz = $0.05
So, the unit rate price per ounce is $0.05.