The value of $$\frac{2}{5}+\left(\frac{1}{1+\frac{5}{7}}\right)-\frac{2}{5}$$​​

Correct option is C

Given: ​

​$$\frac{2}{5}+\left(\frac{1}{1+\frac{5}{7}}\right)-\frac{2}{5}$$ 

Solution: 

​$$\frac{2}{5}+\left(\frac{1}{1+\frac{5}{7}}\right)-\frac{2}{5} \\ \ \\ = \frac{2}{5}+\left(\frac{1}{\frac{7 +5}{7}}\right)-\frac{2}{5} \\ \ \\ = \frac{2}{5}+\left(\frac{7}{{12}}\right)-\frac{2}{5} \\ \ \\ = \frac{7}{{12}}$$​​