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
Refer to the given series and answer the question that follows (all numbers are single-digit numbers only, and all counting is to be done from left to right).
How many such even digits are there, each of which is immediately preceded by a perfect square and immediately followed by an even digit? (Note: 1 will be considered as a perfect square.)
3
6
4
5
3
Scan the sequence for triplets: (Perfect Square, Even Digit, Even Digit). Treat '1' as a perfect square.
Scan the sequence for triplets: (Perfect Square, Even Digit, Even Digit). Treat '1' as a perfect square.
Define criteria
We need to find even digits (2, 4, 6, 8) that are: (1) Immediately preceded by a perfect square (1, 4, 9) and (2) Immediately followed by an even digit (2, 4, 6, 8).
Analyze the series
Series: 2, 2, 3, 3, 1, 7, 8, 4, 2, 8, 6, 5, 4, 3, 9, 1, 4, 2, 1, 2, 9, 1, 6, 2, 3, 4, 8, 1. Scanning for (Square, Even, Even): 1-4-2 (Matches), 1-6-2 (Matches). Checking others: 1-2-9 (9 is not even), 4-8-1 (1 is not even).
Final verification
The matching sets are: 1, 4, 2 (4 is the even digit) and 1, 6, 2 (6 is the even digit). No other segments satisfy the 3-digit condition.
B: 1 is incorrect as we found 2 matches. C: 3 is incorrect because only two sequences fit the criteria. D: 4 is incorrect as the count is 2.
A is correct because the two digits satisfying the conditions are 4 (preceded by 1, followed by 2) and 6 (preceded by 1, followed by 2).
Always verify the 'Note' section (like '1 is a perfect square') as it is a common trap in competitive exams to change standard assumptions.
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