Question 1

Four of the following five are alike in a certain way and so form a group. Which is the one that does not belong to that group?
(1) Crow
(2) Vulture
(...

Accepted Answer

1.  Analyze the biological properties of each option:
    *   *Crow, Vulture, Ostrich, and Eagle* belong to the biological class Aves (Birds). They possess feathers, beaks, and lay eggs.
    *   *Bat* belongs to the class Mammalia (Mammals). It gives birth to live young ones and feeds them milk.
2.  Therefore, Bat is the odd one out because it is the only mammal in the group.
Answer: (3) Bat

Question 2

Four number-pairs have been given, out of which three are alike in some manner and one is different. Select the number-pair that is different from the...

Accepted Answer

1.  Identify the relationship between the fractions ($x/y$) and the single integers ($z$):
    Test the sum of squares of the numerator ($x$) and denominator ($y$) against the integer value $z$ ($x^2 + y^2 = z$).
2.  Calculate for each option:
    *   Option (b): $7^2 + 3^2 = 49 + 9 = 58$. (Matches)
    *   Option (c): $18^2 + 9^2 = 324 + 81 = 405$. (Matches)
    *   Option (d): $5^2 + 6^2 = 25 + 36 = 61$. (Matches)
    *   Option (a): $12^2 + 21^2 = 144 + 441 = 585 
eq 565$. (Does not match)
3.  Since option (a) does not satisfy the formula $x^2 + y^2 = z$, it is the odd one out.
Answer: (a) 12/21, 565

Question 3

Four letter-clusters have been given, out of which three are alike in some manner and one is different. Select the odd letter-cluster.
(a) ADHK
(b) FI...

Accepted Answer

1.  Convert each letter to its positional value in the English alphabet ($A=1, B=2, \dots, Z=26$):
    *   $ADHK 	o [1, 4, 8, 11]$
    *   $FIMP 	o [6, 9, 13, 16]$
    *   $PSVZ 	o [16, 19, 22, 26]$
    *   $ZCGJ 	o [26, 3, 7, 10]$
2.  Analyze the difference patterns between consecutive letters in each group:
    *   Cluster (a) $ADHK$:
        *   $4 - 1 = +3$
        *   $8 - 4 = +4$
        *   $11 - 8 = +3$
        *   *Difference pattern:* $(+3, +4, +3)$
    *   Cluster (b) $FIMP$:
        *   $9 - 6 = +3$
        *   $13 - 9 = +4$
        *   $16 - 13 = +3$
        *   *Difference pattern:* $(+3, +4, +3)$
    *   Cluster (c) $PSVZ$:
        *   $19 - 16 = +3$
        *   $22 - 19 = +3$
        *   $26 - 22 = +4$
        *   *Difference pattern:* $(+3, +3, +4)$
    *   Cluster (d) $ZCGJ$:
        *   $3 - 26 \equiv 29 - 26 = +3$ (since $C$ is 3rd letter, wrapping around Z)
        *   $7 - 3 = +4$
        *   $10 - 7 = +3$
        *   *Difference pattern:* $(+3, +4, +3)$
3.  Compare the difference patterns:
    Clusters (a), (b), and (d) all follow the step sequence of $(+3, +4, +3)$. Cluster (c) follows the step sequence of $(+3, +3, +4)$.
4.  Therefore, $PSVZ$ is the odd letter-cluster.
Answer: (c) PSVZ

Relationship Sub-Concept	Explanation	Group Characteristics	Example
Biological Class / Taxonomy	Distinguishing animals based on mammal, avian, reptile, or amphibian classes.	Mammals vs. Birds (Aves)	Bat (mammal; others like Crow, Sparrow, Pigeon are birds).
Animal and Sound	Associating an animal with its specific vocalization.	Animal - Vocalization	Cocks - Croak (cocks crow; frogs croak).
Animal and Offspring	Associating an animal with its young one.	Animal - Young One	Baboon - Pup (baboons have infants; pups belong to dogs/seals).
Geographical Parameters	Distinguishing locations by rivers, capitals, power stations, or functions.	Cities on River Ganga	Mathura (on Yamuna; Kanpur, Varanasi, Haridwar are on Ganga).
Product Utility / Economics	Grouping goods by demand relationships.	Complementary Goods vs. Substitutes	Tea - Coffee (substitutes; Shoes-Polish, Car-Petrol are complementary).
Anatomy & Pathology	Differentiating bones, organs, or disease types.	Deficiency Diseases vs. Hormonal	Cretinism (hormonal; Kwashiorkor, Goitre, Marasmus are deficiency).
Grammatical Function	Classifying words by parts of speech.	Conjunctions vs. Adverbs	Again (adverb; Unless, While, But are conjunctions).
Physical Quantities	Classifying variables in classical mechanics.	Vector vs. Scalar quantities	Energy (scalar; Momentum, Acceleration, Force are vectors).

Letter	Pos	Letter	Pos	Letter	Pos	Letter	Pos	Letter	Pos
A	1	F	6	K	11	P	16	U	21
B	2	G	7	L	12	Q	17	V	22
C	3	H	8	M	13	R	18	W	23
D	4	I	9	N	14	S	19	X	24
E	5	J	10	O	15	T	20	Y	25
Z	26

Letter	Value	Opposite	Value	Memory Aid
A	1	Z	26	AtoZ
B	2	Y	25	Boy
C	3	X	24	Crux
D	4	W	23	Dew
E	5	V	22	Eve
F	6	U	21	Full
G	7	T	20	GT Road
H	8	S	19	High School
I	9	R	18	Indian Railways
J	10	Q	17	Jack-Queen
K	11	P	16	Kanpur
L	12	O	15	Love
M	13	N	14	Man

Mathematical Category	Formula / Logical Rule	Example Options	Odd One Out Logic
Perfect Squares & Cubes	$x = k^2$ or $x = k^3$	121, 137, 153, 177, 183	121 (Only perfect square: $11^2$ ).
Square/Cube Offset	$x = k^2 \pm c$ or $x = k^3 \pm c$	226, 290, 170, 122, 360	360 (Others are $k^2 + 1$ : $15^2+1, 17^2+1, 13^2+1, 11^2+1$ ).
Variable Polynomial Trend	$x = n^2 - n$ or $x = n^2 + n$	72, 42, 110, 156, 152	152 (Others follow $n^2 - n$ : $9^2-9, 7^2-7, 11^2-11, 13^2-13$ ).
Exponent Series	$x = 2^n + 1$	5, 9, 17, 33, 7	7 (Others are $2^2+1, 2^3+1, 2^4+1, 2^5+1$ ).
Factorial Series	$x = n!$	120, 720, 5040, 40320, 52480	52480 (Others are factorials of $5, 6, 7, 8$ ).
Digital Operations	Sum of digits equals a constant $C$	721, 910, 811, 651	651 (Sums to 12; others sum to 10).
Pair Difference	$y - x = C$	(62-37), (85-60), (103-78), (74-40)	(74-40) (Difference is 34; others have a difference of 25).
Pair Multiplicative Shift	$y = m \cdot x + c$	(7-18), (9-26), (11-36), (13-42)	(11-36) (Others follow $y = 4x - 10$ ).
Cross-Digit Arithmetic	$z = x^2 + y^2$ (for format $x/y, z$ )	(7/3, 58), (18/9, 405), (12/21, 565)	(12/21, 565) (as $12^2 + 21^2 = 585 \neq 565$ ).
Digit Positional Reversal	$y$ is the reversed digit form of $x$	(27:72), (34:43), (65:56), (42:52)	(42:52) (Digits are not reversed).

Exam	Typical Questions
SSC (CGL / CHSL / MTS)	2–3 questions
Banking (IBPS / SBI)	1–2 questions
Railways (RRB)	1–2 questions

Classification Guide & Practice

Practice Question Papers

Practice Filters

Classification - Set 5 Practice Test

Classification - Set 4 Practice Test

Classification - Set 1 Practice Test

Classification - Set 4 Practice Test

Classification - Set 3 Practice Test

Classification - Set 2 Practice Test

Classification - Set 4 Practice Test

Classification - Set 3 Practice Test

Classification - Set 2 Practice Test

Classification - Set 1 Practice Test

Classification - Set 5 Practice Test

Classification - Set 3 Practice Test

Classification - Set 1 Practice Test

1. Fundamentals & Definitions

Definition of Classification

Key Terminology

Types of Classification Questions

2. Core Concepts & Formulas

Word Classification (Semantic Relationships)

Letter Classification (Alphabetical Patterns)

Alphabet Positional Reference Table

Opposite Letters (Sum of positions = 27)

Common Letter Clusters Rules

Number Classification (Numerical Properties)

Typical Exam Weightage

Solved Examples

Letter	Pos	Letter	Pos	Letter	Pos	Letter	Pos	Letter	Pos
A	1	F	6	K	11	P	16	U	21
B	2	G	7	L	12	Q	17	V	22
C	3	H	8	M	13	R	18	W	23
D	4	I	9	N	14	S	19	X	24
E	5	J	10	O	15	T	20	Y	25
Z	26

Letter	Pos	Letter	Pos	Letter	Pos	Letter	Pos	Letter	Pos
A	1	F	6	K	11	P	16	U	21
B	2	G	7	L	12	Q	17	V	22
C	3	H	8	M	13	R	18	W	23
D	4	I	9	N	14	S	19	X	24
E	5	J	10	O	15	T	20	Y	25
Z	26

Letter	Pos	Letter	Pos	Letter	Pos	Letter	Pos	Letter	Pos
A	1	F	6	K	11	P	16	U	21
B	2	G	7	L	12	Q	17	V	22
C	3	H	8	M	13	R	18	W	23
D	4	I	9	N	14	S	19	X	24
E	5	J	10	O	15	T	20	Y	25
Z	26