To find the percentage of boys in the class, you can use the formula for percentage:

$\text{Percentage of boys} = \left(\frac{\text{Number of boys}}{\text{Total number of students}}\right) \times 100$

Given:

• Number of boys = 12
• Total number of students = 21

$\text{Percentage of boys} = \left(\frac{12}{21}\right) \times 100 \approx 57.14\%$

So, approximately 57.14% of the class are boys.

Would you like further details or have any other questions?

Here are 5 related questions:

1. What percentage of the class is girls?
2. If 5 more boys join the class, what percentage will be boys?
3. How many boys would be needed for boys to make up 75% of the class?
4. What is the ratio of boys to girls in the class?
5. If there are 30 students in another class and 18 are boys, what is the percentage of boys?

Tip: Always double-check your ratios by simplifying them to fractions before converting them to percentages.