Postgraduates in the hostel — Caselets Aptitude Question
Postgraduates in the hostel: A hostel houses 450 students, of whom 60% are undergraduates and the rest postgraduates. Answer and worked solution on CodeKairo.
- Topic: Caselets
- Section: Data Interpretation
- Difficulty: Easy
- Time target: 60 seconds
Question
A hostel houses 450 students, of whom 60% are undergraduates and the rest postgraduates. Half the postgraduates are women.
How many postgraduate men are there?
Options
- 80
- 90
- 100
- 110
Show the answer and the worked solution
Correct answer: B. 90
Worked solution
- Postgraduates = 40% of 450 = 180.
- Men = half of 180 = 90.
Answer: 90.
The idea
Work out the subgroup size first, then split it. Each percentage applies only to the group it describes.
Shortcut. Postgraduate men are 40% × ½ = 20% of the hostel, and a fifth of 450 is 90.
Common trap. 100 — rounding 450 up to 500 for easy arithmetic (40% of 500 = 200, half of it 100); the true postgraduate count is 180.