There are 20 girls and 15 boys in a class.
What is the ratio of number of girls to the total number of students in the class?

Answer

To find the ratio of the number of girls to the total number of students in the class, we can follow these steps:

### Step 1: Identify the number of girls and boys
- There are 20 girls and 15 boys in the class.

### Step 2: Calculate the total number of students
- Total number of students = Number of girls + Number of boys
- Total number of students = 20 + 15 = 35

### Step 3: Set up the ratio of girls to total students
- The ratio of the number of girls to the total number of students can be expressed as:
\[ \text{Ratio of girls to total students} = \frac{\text{Number of girls}}{\text{Total number of students}} = \frac{20}{35} \]

### Step 4: Simplify the fraction
- To simplify the fraction \(\frac{20}{35}\), we find the greatest common divisor (GCD) of 20 and 35, which is 5.
- Divide both the numerator and the denominator by 5:
\[ \frac{20 \div 5}{35 \div 5} = \frac{4}{7} \]

### Step 5: Write the ratio
- Now we can express the simplified fraction as a ratio:
\[ \text{Ratio of girls to total students} = 4 : 7 \]

### Final Answer
The ratio of the number of girls to the total number of students in the class is \(4 : 7\).

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