Q.10. The value of ${\tan }^2\frac{\mathrm{\pi }}{16}+{\tan }^2\frac{2\mathrm{\pi }}{16}+{\tan }^2\frac{3\mathrm{\pi }}{16}+.....{\tan }^2\frac{7\mathrm{\pi }}{16}$ is equal to k then the value of $\frac{k}{5}$ is