Select the number that can replace the question mark (?). 28, 32, 41, 57, ?

Question

Select the number that can replace the question mark (?). 28, 32, 41, 57, ?

1. A. 28
2. B. 82 (Correct answer)
3. C. 156
4. D. 981

Correct Answer

Option B — 82

Detailed Solution & Explanation

The correct answer is 82.

Key Points

• This is a difference-of-squares series.
• Examine the gaps between consecutive terms.
• Series: 28, 32, 41, 57, ?
• 32 − 28 = 4 = 2²
• 41 − 32 = 9 = 3²
• 57 − 41 = 16 = 4²
• The differences are consecutive perfect squares (2², 3², 4²), so the next difference is 5² = 25:
• 57 + 25 = 82.
• when first differences are not constant, look at whether they form a recognisable pattern — here they are successive squares.
• Always compute the differences first before guessing a multiplicative rule.

Exam Tip

• the sequences of added values 1,4,9,16,25 (squares) and 2,6,12,20 (n²+n) are the two most common hidden patterns in JKSSB number-series questions — memorise both.