To find the unit rate price per ounce for the hot chocolate, you divide the total cost by the number of ounces.
The total cost is $5.00, and the quantity is 20 ounces.
Unit price per ounce = Total cost / Total ounces
Unit price per ounce = $5.00 / 20 oz = $0.25 per ounce
So, the unit rate price per ounce for her hot chocolate is $0.25.