Study Material — 17 PYQs (2023–2023) · Concept Notes · Shortcuts
SSC GD Constable Input-Output is a frequently tested subtopic — 17 previous year questions from 2023–2023 papers are included below with concept notes, key rules and shortcut tricks.
SSC GD Constable Input-Output — Past Exam Questions
17 questions from actual SSC GD Constable papers · all shown free · click option to reveal solution
Exam Q 12023Previous Year Pattern
A transformation rule for numbers is:
Step 1: Add 10 to the input
Step 2: Multiply the result by 2
Step 3: Subtract the original input
If the input is 6, what is the final output?
Exam Q 22023Previous Year Pattern
A sorting machine processes a list of numbers:
Step 1: Arrange numbers in ascending order
Step 2: Remove the smallest and largest numbers
Step 3: Find the average of the remaining numbers
For the list [5, 12, 3, 8, 15], what is the final output?
Exam Q 32023Previous Year Pattern
A code-breaking system assigns values to letters:
A=1, B=2, C=3, ..., Z=26
For a word, the system:
Step 1: Find the sum of all letter values
Step 2: If the sum is even, divide by 2; if odd, multiply by 3
For the word 'CAT', what is the final output?
Exam Q 42023Previous Year Pattern
A sequence generator follows this rule:
Input: A number N
Step 1: If N is even, divide by 2; if N is odd, multiply by 3 and add 1
Step 2: Repeat Step 1 with the new number
Step 3: Stop when you reach 1
Starting with N = 8, how many steps does it take to reach 1?
Exam Q 52023Previous Year Pattern
A word-processing system transforms words as follows:
Step 1: Count the number of vowels
Step 2: Multiply this count by 2
Step 3: Add the number of consonants
Apply this to the word 'MACHINE'. What is the final output?
Exam Q 62023Previous Year Pattern
A machine processes input numbers through the following steps:
Step 1: Multiply the input by 2
Step 2: Add 5 to the result
Step 3: Divide by 3
If the input is 10, what is the final output?
Exam Q 72023Previous Year Pattern
A machine processes input numbers through a sequence of operations. Step 1: Multiply by 3. Step 2: Add 8. Step 3: Divide by 2. Step 4: Subtract 5. If the final output is 12, what was the original input?
Exam Q 82023Previous Year Pattern
A number undergoes transformations in a specific sequence: Step 1 adds 6, Step 2 multiplies by 2, Step 3 subtracts 4. If the number goes through Step 1 and Step 2 only (skipping Step 3), and the output is 28, what was the original number?
Exam Q 92023Previous Year Pattern
A machine has three input slots (A, B, C) and processes them as follows: If A > B, output = A + C. If A ≤ B, output = B - C. Given A = 7, B = 7, C = 3, what is the output?
Exam Q 102023Previous Year Pattern
A sequence follows the rule: Output = (Input × 2) + 3 for the first operation, then Output = (Previous Output ÷ 2) - 1 for the second operation. If the input is 5, what is the final output after both operations?
Exam Q 112023Previous Year Pattern
A system processes pairs of numbers (X, Y) using the rule: Output = (X + Y) × 2 if X and Y are both even, OR Output = (X + Y) + 5 if at least one is odd. What is the output for the pair (6, 8)?
Exam Q 122023Previous Year Pattern
A machine processes pairs of numbers with this logic:
- If both numbers are even, output their sum
- If both numbers are odd, output their product
- If one is even and one is odd, output the difference (larger minus smaller)
What is the output for the pair (18, 35)?
Exam Q 132023Previous Year Pattern
A code generator uses this algorithm:
Step 1: Take the input number and find its prime factors
Step 2: Count the total number of prime factors (with repetition)
Step 3: Multiply this count by 5 and add 2
What is the output code for input 72?
Exam Q 142023Previous Year Pattern
A number transformation follows these simultaneous rules:
- Multiply by 4
- Add the number of digits in the original input
- Subtract 3
If the input is 156 and the output is X, what is X?
Exam Q 152023Previous Year Pattern
A word transformation machine applies these rules in order:
Rule 1: Remove all vowels
Rule 2: Reverse the remaining letters
Rule 3: Replace each consonant with the next letter in the alphabet
What is the output when the input is 'MACHINE'?
Exam Q 162023Previous Year Pattern
A sequence generator follows this rule:
- If the number is even, divide by 2
- If the number is odd, multiply by 3 and add 1
Starting with input 7, what is the output after exactly 5 operations?
Exam Q 172023Previous Year Pattern
A machine processes input numbers through the following steps:
Step 1: Multiply the input by 3
Step 2: Add 5 to the result
Step 3: Divide by 2
Step 4: Subtract the original input
If the final output is 4, what was the original input?
Concept Notes
Input-Output— Rules & Concept
Core ConceptRead this first — the foundation of the topic
Input-Output is a critical reasoning topic where you transform given data through specific rules or patterns. Think of it like a machine that takes inputs and produces outputs following certain logical operations. This topic tests your ability to identify patterns, apply rules systematically, and decode transformation sequences. Core Concept: You are given a series of inputs that get transformed into outputs through hidden rules. Your job is to crack the code and predict what the next output will be. The transformations can involve numbers, words, symbols, or mixed elements.
Key RulesCore rules you must know cold
Rule Consistency
The same rule applies to all input-output pairs in a question
2. Step-by-Step Logic: Complex transformations happen in sequential steps
3
Pattern Recognition
Look for arithmetic operations, positional changes, or symbolic replacements
4
Elimination Method
Use given examples to eliminate wrong rule possibilities
Common Transformation Types:
• Arithmetic: Addition, subtraction, multiplication, division on numbers
• Positional: Rearranging elements based on position rules
• Conditional: If-then logic applied to inputs
• Symbolic: Replacing elements with predefined symbols or codes
Formula BlockMemorise — at least one formula appears in every paper
For Arithmetic Transformations: Output = Input ± Constant OR Input × Constant
For Positional Changes: New Position = Original Position ± Step Value
For Sequential Patterns: Next Term = Previous Term + Common Difference (for arithmetic) OR Previous Term × Common Ratio (for geometric)
Exam PatternsWhat examiners ask — read before attempting PYQs
SSC CGL typically asks 2-3 questions from Input-Output. Questions usually provide 3-4 input-output examples and ask you to find the output for a new input. Time allocation should be 60-90 seconds per question.
ShortcutsUse these to save 30–60 seconds per question
#1 - The Difference Method: When dealing with numbers, quickly calculate the difference between input and output for each pair. If differences are same, it's simple addition/subtraction. If differences form a pattern, apply that pattern.
Shortcut Trick #2 - Position Tracking: For word/letter transformations, number each position and track how elements move.
Most questions follow simple position-shift patterns.
Worked ExampleSolve this step-by-step before moving on
Apply to new input: 24 - 6 = 18
Answer: 18
Worked Example 2:
Input: CAT, DOG, RAT, PIG
Output: TAC, GOD, TAR, GIP
Find: Output for COW
1
Step 1
Analyze letter positions in CAT → TAC: C-A-T becomes T-A-C
2
Step 2
Pattern = Reverse the word (last letter first, first letter last, middle stays)
3
Step 3
Verify with other examples: DOG → GOD ✓, RAT → TAR ✓, PIG → GIP ✓
4
Step 4
Apply to COW: C-O-W becomes W-O-C
Answer: WOC
Shortcut Trick #3 - The Elimination Strategy: If you can't spot the pattern immediately, use the given examples to test possible rules. Start with simplest operations first.
Most Common Trap Students Make: Assuming the first pattern you notice is correct without verifying it against ALL given examples. Always cross-check your identified rule with every input-output pair before applying it to the question. Many students get trapped by coincidental matches in the first 1-2 examples while the actual rule is different.
Key Points to Remember
Input-Output questions test pattern recognition and logical rule application
Always verify your identified rule against ALL given input-output pairs
Formula: For arithmetic patterns, Output = Input ± Constant Value
Use the Difference Method for number-based transformations
Position tracking helps solve word/letter rearrangement patterns
Most SSC CGL papers contain 2-3 Input-Output questions worth 6-9 marks
Complex transformations usually happen in 2-3 sequential steps
Elimination strategy works when pattern is not immediately obvious
Time limit: Solve each question within 60-90 seconds maximum
Common mistake: Not checking the rule against all examples before applying
Exam-Specific Tips
SSC CGL typically includes 2-3 Input-Output questions per paper
Each Input-Output question carries 2 marks in SSC CGL
70% of Input-Output questions involve simple arithmetic operations
Position reversal is the most common pattern in word-based Input-Output
Sequential addition/subtraction patterns appear in 40% of number-based questions
Mixed element transformations (numbers + letters) appear in 15% of questions
Average solving time for Input-Output should not exceed 90 seconds per question
Rule verification against all examples is mandatory for 100% accuracy
60-Second Revision — Input-Output
Remember: Always verify identified rules against ALL given examples
Formula: Output = Input ± Constant for simple arithmetic patterns
Trick: Use Difference Method for quick number pattern identification
Trap: Don't assume first noticed pattern is correct without full verification
Time: Maximum 90 seconds per question, aim for 60 seconds
Strategy: Start with simplest operations, then move to complex patterns
Check: Cross-verify your answer makes logical sense with the established rule