1. The problem statement, all variables and given/known data A film of gasoline (n= 1.40) floats on glass (n = 1.52). Yellow light (wavelength = 580 nm in vacuum) shines perpendicularly on the film. Determine the minimum nonzero thickness of the film, such that the film appears bright yellow due to constructive inteference 2. Relevant equations 2t + 1/2*wavelength(film) = wavelength(film) 3. The attempt at a solution I know the constructive interference equation is setup like 2t + 1/2*wavelength(film) = wavelenght(film). However, I am having difficulty determining which n value i should use to get the wavelenghth of the film. I know this can be an easy problem for some people so i appreciate all the help i can get. Thanks!