Number Series

Common Patterns

1. Addition/Subtraction Series

2, 5, 8, 11, 14, ?
Pattern: +3
Answer: 17

2. Multiplication/Division Series

3, 6, 12, 24, 48, ?
Pattern: ×2
Answer: 96

3. Square/Cube Series

1, 4, 9, 16, 25, ?
Pattern: 1², 2², 3², 4², 5², 6²
Answer: 36

4. Prime Number Series

2, 3, 5, 7, 11, ?
Pattern: Prime numbers
Answer: 13

5. Mixed Operations

2, 6, 12, 20, 30, ?
Pattern: n×(n+1)
1×2, 2×3, 3×4, 4×5, 5×6, 6×7
Answer: 42

6. Alternating Series

2, 5, 4, 7, 6, 9, ?
Two series: 2,4,6,? (+2) and 5,7,9 (+2)
Answer: 8

7. Fibonacci Type

1, 1, 2, 3, 5, 8, ?
Pattern: Add previous two
Answer: 13

Letter Series

Pattern Types

1. Positional Pattern

A, C, E, G, I, ?
Pattern: Skip 1 letter
Answer: K

2. Reverse Pattern

Z, X, V, T, R, ?
Pattern: -2 positions
Answer: P

3. Mixed Pattern

A, D, H, M, ?
Pattern: +3, +4, +5, +6
Answer: S

4. Vowel/Consonant Pattern

A, E, I, O, ?
Pattern: Vowels only
Answer: U

Letter Positions (Memorize!)

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

Logical Series

Example 1: Word Series

Monday, Wednesday, Friday, ?
Pattern: Alternate days
Answer: Sunday

Example 2: Time Series

1:00, 2:30, 4:00, 5:30, ?
Pattern: +1:30 hours
Answer: 7:00

Important Tricks

Trick 1: Check Differences

If series: 3, 7, 13, 21, 31
Differences: 4, 6, 8, 10
Pattern in differences: +2
Next difference: 12
Answer: 31+12 = 43

Trick 2: Check Ratios

If series: 2, 6, 18, 54
Ratios: ×3
Answer: 54×3 = 162

Trick 3: Odd/Even Split

Check if odd and even positions follow different patterns

Trick 4: For Letters

Convert to numbers, find pattern, convert back

Solved Examples

Q1: Find next: 5, 11, 23, 47, 95, ?

Solution:

Pattern:
5×2+1 = 11
11×2+1 = 23
23×2+1 = 47
47×2+1 = 95
95×2+1 = 191
Answer: 191

Q2: Find next: B, D, G, K, P, ?

Solution:

Positions: 2, 4, 7, 11, 16, ?
Differences: 2, 3, 4, 5, ?
Next difference: 6
16+6 = 22 = V
Answer: V

Q3: Find wrong number: 2, 6, 12, 20, 30, 40

Solution:

Pattern: n(n+1)
1×2=2, 2×3=6, 3×4=12, 4×5=20, 5×6=30, 6×7=42
Wrong number: 40 (should be 42)

Quick Recognition Guide

💡 Pro Tip: Practice 20 series questions daily. Look for differences, ratios, and squares/cubes first!