If 12 is 30% of a number, what is the number?

To find the number of which 12 is 30%, you can set up an equation based on the definition of percentage. If we let the unknown number be represented as ( x ), the relationship can be expressed mathematically as:

[ 30% \text{ of } x = 12 ]

This can be rewritten in equation form as:

[ 0.30x = 12 ]

To isolate ( x ), divide both sides of the equation by 0.30:

[ x = \frac{12}{0.30} ]

Calculating ( \frac{12}{0.30} ) gives:

[ x = 12 \div 0.30 = 40 ]

This confirms that the value of the number is 40. Therefore, since 12 is indeed 30% of 40, the correct answer is 40.

Understanding this process emphasizes the method of converting percentages into decimal form and solving for the unknown quantity systematically.