If the ratio of milk chocolate to dark chocolate is 2:3, we can represent the number of milk chocolates as \(2x\) and the number of dark chocolates as \(3x\).
Given that there are 8 milk chocolates, we can set up the equation:
\[ 2x = 8 \]
To find \(x\), divide both sides by 2:
\[ x = 4 \]
Now, we can find the number of dark chocolates:
\[ 3x = 3 \times 4 = 12 \]
Thus, there are 12 dark chocolates in the box.