To maximize boys, we need to maximize total students first, then find what fraction can be boys.
Let's work through this step by step:
Step 1: Find Maximum TeachersWe're told: Teachers/Support Staff
≤ 3/2Since support staff =
5:
Teachers/5 ≤ 3/2
Teachers ≤
7.5Maximum teachers = 7 (must be a whole person!)Step 2: Find Maximum StudentsWe're told: Students/Teachers
< 18 (notice:
strictly less than, not "at most")
Students/7 < 18
Students <
126Maximum students = 125 (since we need strictly LESS than 126)Common trap: Using ≤ instead of < would give 126 students — but that violates the "less than" condition!Step 3: Find Maximum BoysWe're told: At least
2/3 of students must be girls, but no more than
4/5If at least 2/3 are girls → at most 1/3 can be boysMaximum boys = (1/3) × 125 =
41.67Maximum boys = 41 (must be a whole person!)Quick Verification:• Boys = 41, Total students = 125 → Girls = 84
• Girls/Students = 84/125 = 67.2%
• Is 67.2% between 66.67% (2/3) and 80% (4/5)?
Yes!Answer: C (41)Principle for similar problems: When you see multiple constraints, chain them together starting from what you know. And always watch out for "less than" vs "at most" - one gives you the boundary value, the other doesn't!