In a tank, a 4cm thick layer of water `(mu=4/3)` floats on a 6 cm thick layer of an organic liquid (`mu` = 1.5). Viewing at normal incidence, how far below the water surface does the bottom of tank appear to be?

Explanation

To solve the problem, we need to determine how far below the water surface the bottom of the tank appears to be when viewed from above. We will use the concept of apparent depth, which takes into account the refractive indices of the fluids involved.

### Step-by-Step Solution:

1. **Identify the Given Data:**
- Thickness of water layer, \( t_w = 4 \, \text{cm} \)
- Refractive index of water, \( \mu_w = \frac{4}{3} \)
- Thickness of organic liquid layer, \( t_o = 6 \, \text{cm} \)
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