To determine the extremes of the proportion \( \frac{3}{15} = \frac{12}{60} \), we need to identify the first and last terms of the proportion. In any given proportion of the form \( \frac{a}{b} = \frac{c}{d} \), the extremes are the terms \( a \) and \( d \).
Let's break down the given proportion step by step:
1. The given proportion is:
[tex]\[
\frac{3}{15} = \frac{12}{60}
\][/tex]
2. In the proportion \( \frac{3}{15} = \frac{12}{60} \), the first term is the numerator of the first fraction, which is \( 3 \).
3. The last term is the denominator of the second fraction, which is \( 60 \).
Therefore, the extremes of the proportion \( \frac{3}{15} = \frac{12}{60} \) are 3 and 60.
So, the correct answer is:
C. 3 and 60