What fraction is equivalent to 1/3?

There are infinite number of fractions that are equal to ${\displaystyle \frac{13}{}}$
You can multiply the numerator and denominator of ${\displaystyle \frac{13}{}}$ by any number and the resulting fraction would be equal to ${\displaystyle \frac{13}{}}$ so long as you are multiplying both by the same number.
For example:
${\displaystyle \frac{1}{3}=\frac{1\cdot 2}{3\cdot 2}=\frac{2}{6}}$
${\displaystyle \frac{1}{3}=\frac{1\cdot 4000}{3\cdot 4000}=\frac{4000}{12000}}$
and so on and so forth.

Explanation:
There are many fractions which are equivalent to ${\displaystyle \frac{13}{}}$ but this is the simplest form.
To find an equivalent fraction, multiply ${\displaystyle \frac{13}{}}$ by 1, but with 1 written as ${\displaystyle \frac{22}{,}\frac{33}{,}\frac{44}{}}$ etc
Multiplying the numerator and denominator by the same number does not change the value of a fraction.
${\displaystyle \frac{13}{\times }=\frac{26}{}}$
${\displaystyle \frac{13}{\times }\frac{77}{=}\frac{7}{21}}$
${\displaystyle \frac{13}{=}\frac{26}{=}\frac{39}{=}\frac{4}{12}=\frac{5}{15}=\frac{9}{27}=\frac{14}{42}=\frac{17}{51}=\frac{50}{150}}$ etc

Understood. Thanks.