The ratio of the size of School A to the size of School B is 12 : 13.Express the size of School A as a fraction of the size of School B.

1. ### Break Down the Problem

To express the size of School A as a fraction of the size of School B, we need to understand the current ratio of their sizes. The ratio given is 12:13.

2. ### Relevant Concepts

The ratio can be expressed mathematically as: $\text{Size of School A} : \text{Size of School B} = 12 : 13$ To express the size of School A as a fraction of the size of School B, we can use the formula: $\text{Fraction} = \frac{\text{Size of School A}}{\text{Size of School B}}$

3. ### Analysis and Detail

From the ratio:

• Let the size of School A be $12x$ and the size of School B be $13x$ for some positive number $x$.
• Therefore: $\text{Fraction} = \frac{12x}{13x}$
• Simplifying this expression: $\text{Fraction} = \frac{12}{13}$

4. ### Verify and Summarize

The fraction $\frac{12}{13}$ confirms that the size of School A relative to School B is accurately derived from their ratio.

Final Answer

The size of School A as a fraction of the size of School B is $\frac{12}{13}$.