Ranks by gender composition: In a class of 60, girls are twice the number of boys. Kamal is 17th from the top, with 9 girls ahead of him. How many boys are ranked after Kamal?

Introduction / Context:We combine overall gender counts with position data to compute how many boys trail Kamal.

Given Data / Assumptions:

• Total = 60; girls are twice boys ⇒ boys = 20, girls = 40.
• Kamal ranks 17th from top.
• There are 9 girls ahead of Kamal.
• Kamal is a boy (typical assumption for this named context).

Concept / Approach:Among the 16 ahead of Kamal, boys_ahead = 16 − 9 = 7. Then boys_after = total_boys − boys_ahead − 1 (subtract Kamal himself).

Step-by-Step Solution:

Verification / Alternative check:Sanity: boys not ahead or Kamal himself must be behind, and 12 is consistent.

Why Other Options Are Wrong:They arise from forgetting to subtract Kamal or miscounting boys among those ahead.

Common Pitfalls:Assuming “girls twice boys” means “boys twice girls”; mixing total vs. ahead subsets.

Final Answer:12