श्रृंखला 2, 5, 11, 20, 32, 47, , 86 में लुप्त संख्या ज्ञात कीजिए:

Question

श्रृंखला 2, 5, 11, 20, 32, 47, , 86 में लुप्त संख्या ज्ञात कीजिए:

1. A. 60
2. B. 65 (Correct answer)
3. C. 58
4. D. 62

Correct Answer

Option B — 65

Detailed Solution & Explanation

The correct answer is 65.

Key Points

• Take first differences: 5−2=3, 11−5=6, 20−11=9, 32−20=12, 47−32=15.
• The differences rise by 3 each time, so the next is 18 → 47 + 18 = 65, and then +21 → 65 + 21 = 86, which matches the given last term.

Exam Tip

• Always verify a series answer against the term after the blank — here 86 confirms 65 and rules out the other options.