To find the unit rate, you need to divide the total cost by the number of items. In this case, you divide the total cost of the apples by the number of apples.
The calculation is as follows:
\[ \text{Unit rate} = \frac{\text{Total Cost}}{\text{Number of Apples}} = \frac{12 \text{ dollars}}{6 \text{ apples}} = 2 \text{ dollars per apple} \]
So the unit rate is $2 per apple.