Answer:

Step-by-step explanation:
From the question we are told that:
Diffraction grating

Distance b/w Screen and grating length

Distance b/w neighboring maxima and Screen

Generally the equation for grating space is mathematically given by



Generally the equation for small angle approximation is mathematically given by

Therefore for longest wavelength


Therefore the third order maximum equation for the shorter wavelength as



The wavelengths in the light is given as
