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?
Verbal Reasoning
Time Sequence
Difficulty: Medium
Choose an option
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A3
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B7
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C12
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D23
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ENone of these
Answer
Correct Answer: 12
Explanation
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:
Total boys = 20; boys ahead of Kamal = 7.Boys after Kamal = 20 − 7 − 1 = 12.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