In a class IX General Knowledge quiz, 12 students took part. The number of boys is 4 more than the number of girls. How many boys and how many girls participated in the quiz?

Introduction:
This is a straightforward numbers and equations problem involving a total and a difference. You are told how many students participated in a General Knowledge quiz and how many more boys there are than girls. Two simple equations in two variables are enough to find the exact number of boys and girls. Such problems are common in aptitude tests to check basic algebra and logical setup.

Given Data / Assumptions:

• Total participants = 12 students.
• Number of boys is 4 more than the number of girls.
• All participants are either boys or girls, with no other category.

Concept / Approach:
Let the number of girls be G and the number of boys be B. Use the total equation B + G = 12 and the difference equation B = G + 4. Solve these simultaneously. This is a basic example of forming linear equations from a word problem.

Step-by-Step Solution:
Let G = number of girls and B = number of boys.From the statement: B + G = 12.Also, B = G + 4 (boys are 4 more than girls).Substitute B in the total: (G + 4) + G = 12.2G + 4 = 12 => 2G = 8 => G = 4.Then B = G + 4 = 4 + 4 = 8.So there are 8 boys and 4 girls.

Verification / Alternative check:
Check the total: 8 + 4 = 12. Check the difference: 8 is exactly 4 more than 4. Both conditions given in the question are satisfied, so the answer is correct.

Why Other Options Are Wrong:
7 boys and 5 girls: total 12 but the difference is only 2, not 4.9 boys and 3 girls: difference 6, not 4.6 boys and 6 girls: difference 0, not 4.10 boys and 2 girls: difference 8, not 4.

Common Pitfalls:
Reversing the difference and writing G = B + 4 instead of B = G + 4.Guessing numbers by trial and error instead of setting up simple equations.Forgetting that the sum must exactly match the total of 12 participants.

Final Answer:
8 boys and 4 girls