A beaker exactly full of water has an ice piece floating on it. As the cube melts what happens to the water level if (a) the cube contains an air bubble, (b) the cube contains (i) a lead piece and (ii) a cork piece.

Explanation

To solve the problem, we need to analyze the three different scenarios involving the melting of an ice cube that is floating in a beaker filled with water. We will consider the effects of an air bubble, a lead piece, and a cork piece inside the ice cube.

### Step-by-Step Solution:

1. **Understanding the Initial Condition**:
- The beaker is filled to the brim with water, and an ice cube is floating on it. The ice cube displaces a certain volume of water equal to the weight of the ice cube.

2. **Case (a): Ice Cube Contains an Air Bubble**:
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