Interference $**$

White light is normally incident on two glass microscope slides with a thin layer of air of variable thickness between the slides. Which visible wavelengths interfere constructively when reflected at a point where the air layer is $767$ nm thick?

What is the longest visible wavelength that interferes constructively?

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Incorrect answer.

Marks for this submission: $\frac{0\mathrm{.}000}{0\mathrm{.}500}.$ This submission attracted a penalty of $0\mathrm{.}025.$ Total penalties so far: $0\mathrm{.}050.$

What is the shortest visible wavelength that interferes constructively?

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