Compute each part of given question:
Question: A beam of light in air strikes a glass slab at normal incidence. The glass slab has an index of refraction of 1.50.
Part A: Approximately what percentage of the incident light intensity is transmitted through the slab (in one side and out the other)?
%
Part B: Repeat Part (A) if the glass slab is immersed in water.
%
Please, try to provide detailed explanation for above question. Thanks.