A bird looking down vertically into a pond from 12cm above the surface sees a fish apparently 18 cm below the surface. What is the actual depth of the fish? What is the apparent height of bird as seen by the fish? [Refractive index of water = 4/3]

Explanation

To solve the problem, we need to determine two things: the actual depth of the fish and the apparent height of the bird as seen by the fish. We will use the concept of apparent depth and the refractive index of water.

### Step-by-Step Solution:

1. **Identify Given Values:**
- Height of the bird above the water surface (h) = 12 cm
- Apparent depth of the fish (d') = 18 cm
- Refractive index of water (μ) = 4/3
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