To divide fractions, you can multiply the first fraction by the reciprocal of the second fraction.
So, to divide \( \frac{2}{5} \) by \( \frac{3}{7} \), you can write it as:
\[ \frac{2}{5} \div \frac{3}{7} = \frac{2}{5} \times \frac{7}{3} \]
Now, multiply the numerators and the denominators:
\[ = \frac{2 \times 7}{5 \times 3} = \frac{14}{15} \]
So, \( \frac{2}{5} \div \frac{3}{7} = \frac{14}{15} \).