Odd-Even Separation Easy

Odd-Even Separation problems present a sequence of numbers as input. Through a series of steps, even numbers are moved to the front (or back) of the sequence, followed by odd numbers, often with each group sorted internally. These problems test your ability to classify numbers by parity and arrange them systematically.

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

Introduction to Odd-Even Separation Easy

Odd-Even Separation problems present a sequence of numbers as input. Through a series of steps, even numbers are moved to the front (or back) of the sequence, followed by odd numbers, often with each group sorted internally. These problems test your ability to classify numbers by parity and arrange them systematically.

Prerequisites

Understanding of odd and even numbers Basic sorting concepts Sequential step tracking Pattern recognition in number movements
Why This Matters: Odd-Even Separation problems appear in 1-2 questions in SSC CGL and Banking PO exams. They test number classification and sorting skills.

How to Solve Odd-Even Separation Easy Problems

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Step 1: Observe the given input sequence of numbers

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Step 2: Analyze the transformation pattern in the provided steps

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Step 3: Identify whether evens go first or odds go first

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Step 4: Determine if each group is sorted internally

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Step 5: Apply the same separation logic to continue the sequence

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Step 6: The final output has all evens (sorted) followed by all odds (sorted) or vice versa

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Step 7: Verify the parity of each number

Pro Strategy: First identify the parity rule (evens first or odds first). Then determine if numbers within each parity group are sorted. The final output will have all numbers of one parity followed by all numbers of the other parity.

Example Problem

Example: Input: '15 42 28 91 56' Step 1: '42 28 56 15 91' Step 2: '28 42 56 15 91' Final Output: '28 42 56 15 91' Solution: Step 1: Even numbers (42,28,56) moved to front Step 2: Evens sorted ascending: 28,42,56; odds (15,91) remain Answer: 28 42 56 15 91

Pro Tips & Tricks

  • Even numbers: divisible by 2 (last digit 0,2,4,6,8)
  • Odd numbers: not divisible by 2 (last digit 1,3,5,7,9)
  • Evens can be sorted ascending or descending
  • Odds can be sorted ascending or descending
  • The order of evens and odds (which comes first) is fixed in the pattern
  • Count how many numbers are even and how many are odd to verify final arrangement

Shortcut Methods to Solve Faster

Final output (evens first) = sorted(evens) + sorted(odds)
Final output (odds first) = sorted(odds) + sorted(evens)
If evens are not sorted, they maintain original relative order within the even group
If odds are not sorted, they maintain original relative order within the odd group

Common Mistakes to Avoid

Confusing even with odd numbers
Forgetting to sort within parity groups when specified
Missing that numbers within a parity group may maintain original order (not sorted)
Not counting the total numbers correctly

Exam Importance

Odd-Even Separation Easy is an important topic for various competitive exams. Here's how frequently it appears:

SSC CGL
1-2 questions
BANKING PO
1-2 questions
RAILWAYS RRB
2-3 questions
INSURANCE
1-2 questions

Ready to Master Odd-Even Separation Easy?

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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