In a class, there are z students. Out of them 'X are boys. What part of the class is composed of girls ?

Options

A. `(x)/(z)`
B. `(z)/(x)`
C. `1-(x)/(z)`
D. `(x)/(z)-1`

Answer

To find the part of the class that is composed of girls, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Total Number of Students**:
- Let the total number of students in the class be represented by \( z \).

2. **Identify the Number of Boys**:
- Out of the total students, let \( x \) be the number of boys.

3. **Calculate the Number of Girls**:
- The number of girls in the class can be calculated by subtracting the number of boys from the total number of students:
\[ \text{Number of girls} = z - x \]

4. **Determine the Part of the Class that is Girls**:
- To find what part of the class is composed of girls, we divide the number of girls by the total number of students:
\[ \text{Part of the class that is girls} = \frac{z - x}{z} \]

5. **Simplify the Expression**:
- The expression can be simplified to:
\[ \frac{z - x}{z} = 1 - \frac{x}{z} \]

### Final Answer:
Thus, the part of the class that is composed of girls is:
\[ 1 - \frac{x}{z} \]