A solid has a cubic structure in which X atoms are located at the corners of the cube, Y atoms are at the cube centres and O atoms are at the edge centres. What is the formula of the compound?

Explanation

To determine the formula of the compound with the given cubic structure, we need to analyze the contributions of each type of atom (X, Y, and O) based on their positions within the cube.

### Step 1: Count the contribution of X atoms
- **Position**: X atoms are located at the corners of the cube.
- **Corners**: A cube has 8 corners.
- **Contribution per corner**: Each corner atom contributes \( \frac{1}{8} \) to the unit cell.

**Calculation**:
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