A swimmer is treading water with their head above the surface of a pool and sees a penny at the bottom of the pool 5.0 mm below. How deep does the coin appear to be? (Index of refraction of water = 1.33) [Conceptual note: Does the coin appear to be shallower or deeper?]

The  apparent depth is  

Explanation:

From the question we are told that

     The  depth of the water is  

      The  refractive index of water is  

Generally the apparent depth of the coin is mathematically represented as

Here    is the refractive index of  air the value is  

So

it has to be b, about 97 percent.