Classification and Matrix

Why This Chapter Matters

Classification (Odd One Out) gives 5-8 questions in SSC. Matrix questions test pattern recognition. Both are reliable scoring areas.

Analogy — Think of Classification like sorting a mixed drawer of tools by what they're actually FOR, not what they look like. Four items might share a superficial trait (all are metal, all are small) while one shares a genuinely different category (three are cutting tools, one is a measuring tool) — the trap is stopping at the first shared trait you notice instead of checking every candidate grouping. Matrix questions are the same underlying skill applied to numbers/shapes in a grid instead of objects in a drawer: find the actual rule connecting cells (by row, then column, then diagonal), not just a pattern that happens to fit the first two you looked at.

Part 1 — Classification (Odd One Out)

Types

Word classification: Three words share a common property; one does not.

Example: Tiger, Lion, Elephant, Cheetah → Elephant (not a big cat).

Example: January, March, July, June → June (31 days? No — Jan/Mar/Jul have 31, June has 30). Odd one: June.

Number classification: Find the number that doesn't follow the pattern.

Example: 16, 25, 36, 49, 64, 77 → All are perfect squares except 77 (8²=64, 9²=81). Odd: 77.

Example: 8, 27, 64, 100, 125 → 100 is not a perfect cube (others are 2³,3³,4³,5³). Odd: 100.

Letter group classification:

Example: BDFH, ACEG, JLNP, MOQS → All skip one letter in sequence; MOQS skips 1 (M,O,Q,S — differences 2). Actually checking: MOQS same pattern. Look for one that breaks the rule.

Strategy

1.Look for obvious groupings (animals, plants, tools, etc.)

2.Check mathematical properties (squares, cubes, prime, odd, even)

3.Check alphabetic properties (vowels/consonants, positions, patterns)

4.Consider multiple angles before deciding — SSC often uses tricky groupings

Common Groupings in SSC

Planets (Mercury,Venus,Earth,Mars — inner; Jupiter,Saturn,Uranus,Neptune — outer)

Prime numbers | Perfect squares | Cubes

Synonyms group | Antonyms to the rest

Countries vs capitals | Tools vs their users

Part 2 — Matrix Questions

Format

A 3×3 or 4×4 matrix where rows/columns follow a pattern. One cell has a ? to find.

Common Patterns

Row sum constant: Each row adds to same number.

Row product constant: Each row has same product.

Column pattern: Each column follows same arithmetic/geometric rule.

Diagonal pattern: Main diagonal or anti-diagonal has a specific relationship.

Mixed: Row sum = Column sum = diagonal sum (magic square).

Magic Square

Sum of every row, column, and diagonal is the same.

Classic 3×3: 2,7,6/9,5,1/4,3,8 — each sums to 15.

SSC often gives 7 of 9 cells and asks for missing two.

Approach

1.Check if rows follow pattern (sum, product, difference, square).

2.Check columns.

3.Check diagonals.

4.Apply found pattern to get missing value.

Solved Examples

Q1 (Classification): 169, 196, 225, 253, 289

Perfect squares: 13²=169, 14²=196, 15²=225, 17²=289. 253 is NOT a perfect square (15²=225, 16²=256). Odd: 253.

Q2 (Matrix):

4	9	2
3	5	7
8	1	?

Rows: 4+9+2=15, 3+5+7=15, 8+1+?=15 → ?=6. Magic square! Each row, column, diagonal=15.

Q3 (Classification): BGLQ, DINT, FJOU, HLPV

Differences in B,G,L,Q → 5,5,5. D,I,N,T → 5,5,6. F,J,O,U → 4,5,6. H,L,P,V → 4,4,6.

Odd one: DINT (5,5,6 not consistent? actually FJOU: F=6,J=10,O=15,U=21: 4,5,6) → check all again more carefully for SSC pattern. In exam: pick the one that clearly breaks the others' rule.

PYQs (SSC)

SSC CGL 2023 (Classification): 17, 19, 23, 29, 31, 35

All prime numbers except 35 = 5×7. Answer: 35.

SSC CGL 2022 (Matrix):

12 → 144 | 15 → 225 | 18 → ?

Pattern: n → n². 18² = 324.

Revision Notes

CLASSIFICATION STRATEGY:
1. Obvious category (animals, tools, etc.)
2. Math property (prime, square, cube, even, odd)
3. Alphabetic property (vowels, position, pattern)
4. Never first guess — check all options

MATRIX APPROACH:
Check row pattern (sum/product/square) first
Then column pattern
Then diagonal pattern
Apply to find missing value

MAGIC SQUARE: every row=column=diagonal. Middle cell = total/3.
Classic 3×3 sum=15, middle cell=5.

Try It (2 Minutes)

Given: Dog, Cat, Lion, Table. Before reading further, pick the odd one out and state WHY in one sentence. Most people correctly say "Table" (not an animal) — but notice the reasoning you used: you checked what category each item belonged to, not a surface trait like size or color. Now try a harder set: Triangle, Square, Circle, Cube. The trap here is subtler — three are 2D shapes, one (Cube) is 3D. If you'd sorted by "has straight edges" instead (Triangle/Square vs Circle/Cube), you'd get a different, wrong answer — which is exactly why checking multiple possible groupings before committing matters more than pattern-matching the first shared trait you spot.