To multiply \( \frac{2}{5} \) by \( -\frac{1}{4} \), you multiply the numerators and the denominators:
\[ \frac{2}{5} \times -\frac{1}{4} = \frac{2 \times -1}{5 \times 4} = \frac{-2}{20} \]
Now, simplify \( \frac{-2}{20} \):
Both the numerator and the denominator can be divided by 2:
\[ \frac{-2 \div 2}{20 \div 2} = \frac{-1}{10} \]
So, the answer in simplest form is:
\[ \frac{-1}{10} \]