Readers of only one paper — Caselets Aptitude Question
Readers of only one paper: In a survey of 500 people, 280 read newspaper A, 220 read newspaper B, and 90 read both. Answer and worked solution on CodeKairo.
- Topic: Caselets
- Section: Data Interpretation
- Difficulty: Easy
- Time target: 50 seconds
Question
In a survey of 500 people, 280 read newspaper A, 220 read newspaper B, and 90 read both.
How many read only newspaper A?
Options
- 170
- 190
- 200
- 220
Show the answer and the worked solution
Correct answer: B. 190
Worked solution
- Only A = 280 − 90 = 190.
Answer: 190.
The idea
'Only A' removes the overlap from A's total. The same subtraction on B gives 130, and 190 + 130 + 90 = 410 as a check.
Shortcut. Only A = readers of at least one paper minus all of B's readers: 410 − 220 = 190.
Common trap. 220 — B's total, the figure printed beside A's in the prompt; 'only A' is A's 280 less the 90 who read both.