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
What should come in place of? in the given series? 12 15 21 33 57?
81
95
105
117
105
Observe the differences between consecutive terms; they follow a geometric progression of powers of 2 (3, 6, 12, 24, 48).
Observe the differences between consecutive terms; they follow a geometric progression of powers of 2 (3, 6, 12, 24, 48).
Calculate the differences between consecutive terms
15 - 12 = 3; 21 - 15 = 6; 33 - 21 = 12; 57 - 33 = 24.
Identify the pattern in differences
The differences are 3, 6, 12, 24. Each difference is double the previous one: 3x2=6, 6x2=12, 12x2=24.
Calculate the next term
The next difference must be 24 x 2 = 48. Adding this to the last term: 57 + 48 = 105.
A: 81 is incorrect because it assumes a linear addition pattern. B: 95 is incorrect as it results from a calculation error in the differences. D: 117 is incorrect as it assumes a higher increment value.
C is correct because the series follows an addition pattern where the difference between terms doubles with each step, leading to 57 + 48 = 105.
If the differences in a series don't form an obvious pattern, always check the difference of the differences (second-order difference) to reveal hidden exponential or geometric growth.