What will come at the place of question mark? 2, 12, 30, 56, 90, ?

Question

What will come at the place of question mark? 2, 12, 30, 56, 90, ?

1. A. 132 (Correct answer)
2. B. 140
3. C. 142
4. D. 150

Correct Answer

Option A — 132

Detailed Solution & Explanation

The correct answer is 132.

Key Points

• Differences: 12 − 2 = 10, 30 − 12 = 18, 56 − 30 = 26, 90 − 56 = 34 — rising by 8 each time.
• The next difference is 42, so the answer is 90 + 42 = 132.
• The same series also reads as consecutive n(n+1) products of odd and even numbers: 1×2, 3×4, 5×6, 7×8, 9×10, 11×12 = 132.

Additional Information

• Two independent routes agreeing on 132 is the strongest confirmation available in a series question.
• The product form is worth recognising: 2, 12, 30, 56, 90, 132 are the pronic-style products of consecutive odd and even pairs.
• If first differences form their own arithmetic progression, the original series is quadratic in n.

प्रश्न (हिन्दी में)

प्रश्नवाचक चिह्न के स्थान पर क्या आएगा? 2, 12, 30, 56, 90, ?

1. A. 132
2. B. 140
3. C. 142
4. D. 150