$\text{If}\frac{2}{5}+x=\frac{3}{5},\text{then}x=$ .

The correct option is B $\frac{1}{5}$
$\text{Given:}\frac{2}{5}+x=\frac{3}{5}\text{On subtracting}\frac{2}{5}\text{from both the sides,}\text{we get,}\frac{2}{5}-\frac{2}{5}+x=\frac{3}{5}-\frac{2}{5}\Rightarrow x=\frac{3-2}{5}=\frac{1}{5}$