Aresearcher measures the thickness of a layer of benzene ( n = 1.50) floating on

Aresearcher measures the thickness of a layer of benzene ( n = 1.50) floating on water by shining monochromatic light onto the film and varying the wavelength of the light. she finds that light of wavelength 565 nm is reflected most strongly from the film. part a: what does she calculate for the minimum thickness of the film? t= need units also.