To divide by a fraction, you can multiply by its reciprocal. Therefore, dividing 12,000 by \( \frac{1}{3} \) is the same as multiplying 12,000 by 3:
\[ 12,000 \div \frac{1}{3} = 12,000 \times 3 = 36,000 \]
So, \( 12,000 \div \frac{1}{3} = 36,000 \).