Carbon Tetrachloride A 30mm thick layer of water (n = 1.33) floats on a50 mm thick layer of carbon tetrachloride (n = 1.46) in a tank. A coin lies at the bottom of the tank. At what depth below the top water surface do you perceive the coin? (Hint: Utilize the result and assumptions of Problem 35 and work by a ray diagram of the situation.)