Join 60,000+ competitive exam aspirants
or with email
Your Cart
SubtotalтВ╣0
TotalтВ╣0
Examoogle тАв User тАв info@examoogle.com тАв EE-2024-8821
Chapter 1 of 12 тАв Page 1 of 248ЁЯФТ Protected PDF тАв Watermarked
Join 60,000+ competitive exam aspirants
Which of the following options should come in place of the question mark (?) in the given series? 7 13 25? 97 193
39
49
32
35
49
Identify the difference between consecutive terms. The differences form a geometric progression multiplied by 2: 6, 12, 24, 48, 96. Adding 24 to 25 gives 49.
Identify the difference between consecutive terms. The differences form a geometric progression multiplied by 2: 6, 12, 24, 48, 96. Adding 24 to 25 gives 49.
Analyze consecutive differences
Find the difference between each term: 13 - 7 = 6, 25 - 13 = 12. The differences double each time (6, 12, 24, 48, 96).
Calculate missing term
The next difference should be 12 x 2 = 24. Adding 24 to the third term (25) gives 25 + 24 = 49.
Verify with subsequent terms
With 49 as the missing term, the next difference is 97 - 49 = 48 (which is 24 x 2), and 193 - 97 = 96 (which is 48 x 2). The pattern is fully verified.
A: 39 is incorrect because the difference from 25 would be 14, which breaks the doubling difference pattern (6, 12, 24). C: 32 and D: 35 do not fit the doubling difference sequence.
Option B is correct because the series follows a pattern of differences that double each step (6, 12, 24, 48, 96), making the missing term 25 + 24 = 49.
When consecutive differences in a number series grow rapidly or follow powers of 2, always check if the differences themselves form a geometric progression or multiplication table.
Get instant step-by-step AI explanations, full shift Previous Year Papers (SSC GD, RRB, SSC JE), and regional rank analysis on the official Examoogle App.
Free Download тАв 100K+ Aspirants