This page covers Rajasthan Police Constable Series Completion with complete concept notes, 56 graded practice MCQs, key points and exam-specific tips. Free to study.
Core ConceptRead this first — the foundation of the topic
Core Concept
Every series has a hidden logic or pattern. Your job is to crack this pattern and find the next or missing term. The pattern can be based on alphabetical order, numerical gaps, positional values, or combinations
Alphabetical Position Rule
A=1, B=2, C=3...
Gap Pattern
Fixed gaps between consecutive letters
3
Reverse Pattern
Series going backwards in alphabet
4
Alternate Pattern
Two different patterns running together
5
Position-based Pattern
Even/odd positions follow different rules
Formula BlockMemorise — at least one formula appears in every paper
- Alphabetical Position: Letter Position = (Letter ASCII value - 64) for capitals
- Gap Formula: Next term = Current term + Fixed gap
- Alternate Series: Odd positions follow Pattern A, Even positions follow Pattern B
- Reverse Counting: Z=1, Y=2, X=3... A=26
Exam PatternsWhat examiners ask — read before attempting PYQs
SSC loves testing gap-based series (+2, +3, +4 patterns), alternate letter series (AE, BF, CG type), and combination series mixing numbers with letters. Most questions are straightforward if you identify the core pattern quickly.
ShortcutsUse these to save 30–60 seconds per question
#1 - The '5-Second Gap Check'
In any letter series, immediately check if there's a consistent gap between consecutive terms
Count positions
A to D = gap of 3, D to G = gap of 3. If gaps match, you've found your pattern.
Worked ExampleSolve this step-by-step before moving on
1
Step 1
Break into individual letters: A-C, F-H, K-M, P-R
2
Step 2
Find gaps in first letters: A(1) to F(6) = +5, F(6) to K(11) = +5, K(11) to P(16) = +5
3
Step 3
Find gaps in second letters: C(3) to H(8) = +5, H(8) to M(13) = +5, M(13) to R(18) = +5
4
Step 4
Pattern confirmed - both positions have +5 gap
5
Step 5
Next term = P(16)+5 = U(21), R(18)+5 = W(23)
Answer: UW
Shortcut Trick #2 - The 'Alphabet Skip Method': When you see letters with big gaps, convert to numbers immediately. It's faster to work with 1,6,11,16 than A,F,K,P.
Worked Example 2: Complete the series: B2D, D6F, F18H, H54J, ?
1
Step 1
Identify pattern structure - Letter+Number+Letter
2
Step 2
First letters: B,D,F,H (gap of +2 each)
3
Step 3
Last letters: D,F,H,J (gap of +2 each)
4
Step 4
Middle numbers: 2,6,18,54
5
Step 5
Number pattern: 2×3=6, 6×3=18, 18×3=54, 54×3=162
6
Step 6
Next first letter: H+2=J, Next last letter: J+2=L
Answer: J162L
Shortcut Trick #3 - The 'Reverse Psychology': If normal alphabetical order doesn't work, try reverse order where A=26, B=25, etc. Many SSC questions use this trick.
#1 Most Common Trap: Students often miss that a series has TWO separate patterns running simultaneously. They solve for one pattern and ignore the other. Always check if odd and even positions follow different rules. For example, in series ACF, BEH, the first letters follow +2 gap (A,B) while the second and third letters follow different patterns.
Another major mistake is confusing alphabetical positions. Remember: A=1, not A=0. This single error can derail your entire solution.
Time Management Tip: Spend maximum 90 seconds per series question. If pattern isn't clear in 30 seconds, try the reverse approach or skip and return later.
Key Points to Remember
Every letter series follows a hidden pattern - find the logic first, then apply
Convert letters to numbers using A=1, B=2... Z=26 for faster calculation
Gap Pattern Formula: Check if consecutive terms have fixed gaps (+2, +3, +4)
Reverse Pattern Formula: Sometimes A=26, B=25... Z=1 is used
Alternate Series Rule: Odd and even positions may follow completely different patterns
5-Second Gap Check: Immediately verify if gaps between consecutive letters are consistent
Alphabet Skip Method: Work with numbers (1,6,11,16) instead of letters (A,F,K,P)
Two-pattern trap: Most errors occur when students miss that series has dual patterns
Time limit: Maximum 90 seconds per question, skip if pattern unclear in 30 seconds
Position counting: A=1 not A=0, this basic error ruins entire calculations
Exam-Specific Tips
A=1, B=2, C=3... Z=26 is the standard alphabetical position formula used in SSC
Most SSC series use gaps of +2, +3, +4, or +5 between consecutive terms