If 3 cookies represent 25% of the cookies that Vince's mom baked, we can set up the equation to find the total number of cookies.
Let \( x \) be the total number of cookies. Since 25% is equal to \( \frac{25}{100} \) or \( \frac{1}{4} \), we can write the equation:
\[ 3 = 0.25 \times x \]
To solve for \( x \), we can multiply both sides by 4:
\[ 12 = x \]
Thus, Vince's mom baked a total of 12 cookies.