10, 100, 200, 310, ? — Aptitude Question
10, 100, 200, 310, ?: Find the next term: 10, 100, 200, 310, ? Answer and worked solution on CodeKairo.
- Topic: Number & Letter Series
- Section: Logical Reasoning
- Difficulty: Medium
- Time target: 50 seconds
Question
Find the next term:
10, 100, 200, 310, ?
Options
- 400
- 420
- 430
- 440
Show the answer and the worked solution
Correct answer: C. 430
Worked solution
- Differences: 90, 100, 110 — rising by 10.
- Next = 310 + 120 = 430.
Answer: 430.
The idea
Large numbers do not change the method: write the differences and look for their own pattern.
Shortcut. Scale down by 10: 1, 10, 20, 31 has gaps 9, 10, 11, so its next term is 43 and the answer is 430.
Common trap. 420 — adding the last gap, 110, again (310 + 110); the gaps rise by 10, so the next is 120.