To solve \( \frac{3}{12} \div \frac{1}{3} \), we can rewrite the division of fractions as multiplying by the reciprocal of the second fraction:
\[ \frac{3}{12} \div \frac{1}{3} = \frac{3}{12} \times \frac{3}{1} \]
Next, we multiply the fractions:
\[ \frac{3 \times 3}{12 \times 1} = \frac{9}{12} \]
Now, we simplify \( \frac{9}{12} \):
To simplify, we can divide the numerator and the denominator by their greatest common divisor (GCD), which is 3:
\[ \frac{9 \div 3}{12 \div 3} = \frac{3}{4} \]
So, the simplified result is \( \frac{3}{4} \).
The answer choice is:
3/4