Sum/Diff Positions

Sum and Difference of Positions problems require you to add or subtract the position numbers of letters. These problems test your basic arithmetic skills applied to alphabet positions. You may be asked to find the sum, difference, or use these operations to decode codes.

10Worksheets
200+Practice Questions
BeginnerDifficulty
1-2 hoursHours to Master

Introduction to Sum/Diff Positions

Sum and Difference of Positions problems require you to add or subtract the position numbers of letters. These problems test your basic arithmetic skills applied to alphabet positions. You may be asked to find the sum, difference, or use these operations to decode codes.

Prerequisites

Alphabet positions (A=1 to Z=26) Basic addition and subtraction Absolute value concept Number comparison
Why This Matters: Sum and Difference of Positions problems appear in 2-3 questions in SSC CGL and Banking PO exams. They are fundamental to coding-decoding sections.

How to Solve Sum/Diff Positions Problems

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Step 1: Identify the letters involved in the problem

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Step 2: Convert each letter to its position number

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Step 3: For sum, add the position numbers together

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Step 4: For difference, subtract the smaller from the larger (or use absolute value)

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Step 5: If the problem asks for a code, the result may be the code itself

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Step 6: For reverse problems, use equations to find unknown letters

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Step 7: Verify calculations and present the answer

Pro Strategy: Always convert letters to numbers first. For difference, always subtract the smaller from the larger unless specified otherwise. For sum problems, addition is straightforward.

Example Problem

Example 1: What is the sum of the positions of 'C', 'A', and 'T'? Solution: Step 1: C=3, A=1, T=20 Step 2: Sum = 3 + 1 + 20 = 24 Answer: 24 Example 2: What is the difference between the positions of 'P' and 'M'? Solution: Step 1: P=16, M=13 Step 2: Difference = 16 - 13 = 3 Answer: 3 Example 3: The sum of positions of two letters is 30. One letter is 'K'. Find the other letter. Solution: Step 1: K=11 Step 2: Other position = 30 - 11 = 19 Step 3: Position 19 = S Answer: S

Pro Tips & Tricks

  • Memorize key positions for quick reference: A=1, E=5, J=10, O=15, T=20, Z=26
  • Sum of A and Z = 27 (the maximum sum for two letters)
  • Sum of M and N = 27 (the middle pair)
  • Difference is always between 0 and 25
  • Two different letter pairs can have the same sum
  • Use equations for reverse problems: unknown = total - known

Shortcut Methods to Solve Faster

Sum = Σ(position of each letter)
Absolute difference = |pos1 - pos2|
Unknown position = total sum - sum of known positions

Common Mistakes to Avoid

Using A=0 instead of A=1 (different coding scheme)
Forgetting absolute value for difference
Subtracting in wrong order for signed difference
Addition errors with larger numbers

Exam Importance

Sum/Diff Positions is an important topic for various competitive exams. Here's how frequently it appears:

SSC CGL
2-3 questions
BANKING PO
2-3 questions
RAILWAYS RRB
2-3 questions

Ready to Master Sum/Diff Positions?

Start with Worksheet 1 and work your way up to expert level! Each worksheet includes:

20 practice questions
Detailed solutions
Step-by-step explanations
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