Find the equivalent ratio of $\frac{12}{13}$with denominator 39.

Two ratios are said to be equivalent if any one of the ratios can be expressed as a multiple of the other. Some examples of equivalent ratios are 1:2 and 3:6, 4:5 and 12:15, etc.

The given ratio is $\frac{12}{13}$.

Let us consider an equivalent ratio of $\frac{12}{13}$ , with denominator 39, to be $\frac{\square }{39}$.

Now,

 $\frac{12}{13}=\frac{\square }{39 }$

By multiplying, numerator and denominator of $\frac{12}{13}$with 3 we get,

$\frac{12\times 3}{13\times 3}=\frac{36}{39}$

Therefore,  the correct answer is $\frac{36}{39}$.