In a Young's double slit experiment the intensity at a point where...

In a Young's double slit experiment the intensity at a point where the path difference is $\frac{\lambda}{6}$ ($\lambda$ being the wavelength of the light used) is $\mathrm{I}$. If $\mathrm{I}_0$ denotes the maximum intensity, \frac{\mathrm{I}}{\mathrm{I}_0} is equal to