3, 6, 11, 18, 27, ? — Aptitude Question
3, 6, 11, 18, 27, ?: Find the next term: 3, 6, 11, 18, 27, ? Answer and worked solution on CodeKairo.
- Topic: Number & Letter Series
- Section: Logical Reasoning
- Difficulty: Easy
- Time target: 45 seconds
Question
Find the next term:
3, 6, 11, 18, 27, ?
Options
- 36
- 38
- 40
- 42
Show the answer and the worked solution
Correct answer: B. 38
Worked solution
- Differences: 3, 5, 7, 9 — consecutive odd numbers.
- Next difference = 11, so the term is 27 + 11 = 38.
Answer: 38.
The idea
Odd-number differences always signal a quadratic. Here the terms are n² + 2.
Shortcut. Subtract 2 from each option: only 38 leaves a perfect square (36), matching the series as 1, 4, 9, 16, 25 raised by 2.
Common trap. 36 — either repeating the last gap (27 + 9) or writing 6² and dropping the + 2 that every term carries.