In Young's double slit experiment, using monochromatic light of wavelength λ, the intensity of light at a point on the screen where the path…

In Young's double slit experiment, using monochromatic light of wavelength $\displaystyle \lambda$, the intensity of light at a point on the screen where the path difference is $\displaystyle \lambda$, is K units. The intensity of light at a point where the path difference is $\displaystyle \frac{\lambda}{3}$ will be :