Please include full solution, formulas, and right answer and please do this asap thanks in advance

6 . For light with a wavelength of 720 nm going through a single slit, what is the path length difference, AB, in nm between the source at the far left side of the slit and the source at the far right side of the slit: * To 2nd min (part a) or 3rd max (part b) a) to the 2nd minimum from the centre b) to the 3rd maximum from the centre? [A4] 7. For green light, A = 540 nm, determine the type of interference (constructive or destructive) on the reflected side for both a) and b). Start with a crest. Show the rays. Write your answer on the reflected and transmitted sides. Also, determine the thickness of the middle layer in nm