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
Select the option that does NOT belong to the same category as the others: 81, 125, 343, 729
81
125
343
729
81
Identify if numbers are perfect cubes or perfect squares; perfect squares and cubes often act as the odd one out in classification sets.
Identify if numbers are perfect cubes or perfect squares; perfect squares and cubes often act as the odd one out in classification sets.
Analyze the mathematical property of each number
Identify the exponential form of each given number: 81 is 9 squared (9 to the power of 2) or 3 to the power of 4. 125 is 5 cubed (5 to the power of 3). 343 is 7 cubed (7 to the power of 3). 729 is 27 squared (27 to the power of 2) or 9 cubed (9 to the power of 3).
Apply classification logic
Comparing the powers: 125 (5 cubed), 343 (7 cubed), and 729 (9 cubed) are all perfect cubes. 81 is a perfect square (9 squared) and is not a perfect cube.
B: 125 is 5 cubed, C: 343 is 7 cubed, and D: 729 is 9 cubed; all these represent perfect cubes.
A is correct because 81 is the only number in the set that is a perfect square and not a perfect cube, while the others are all perfect cubes.
In number classification questions, check for powers (squares and cubes) first as they are the most common patterns in competitive exams.
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