4, 6, 10, 16, 26, ? — Aptitude Question
4, 6, 10, 16, 26, ?: Find the next term: 4, 6, 10, 16, 26, ? Answer and worked solution on CodeKairo.
- Topic: Number & Letter Series
- Section: Logical Reasoning
- Difficulty: Medium
- Time target: 50 seconds
Question
Find the next term:
4, 6, 10, 16, 26, ?
Options
- 36
- 38
- 40
- 42
Show the answer and the worked solution
Correct answer: D. 42
Worked solution
- Each term is the sum of the previous two: 4 + 6 = 10, 6 + 10 = 16, 10 + 16 = 26.
- Next = 16 + 26 = 42.
Answer: 42.
The idea
When differences themselves look like earlier terms, test the Fibonacci rule aₙ = aₙ₋₁ + aₙ₋₂ before anything more elaborate.
Shortcut. Test the rule on the last three: 10 + 16 = 26 confirms add-the-previous-two, so 16 + 26 = 42.
Common trap. 36 — repeating the last gap of 10; each gap equals the term two places back, so the next gap is 16.