Study Material — 12 PYQs (2023–2023) · Concept Notes · Shortcuts
SSC MTS Input-Output is a frequently tested subtopic — 12 previous year questions from 2023–2023 papers are included below with concept notes, key rules and shortcut tricks.
12 questions from actual SSC MTS papers · all shown free · click option to reveal solution
Exam Q 12023Previous Year Pattern
A text processor applies these rules in sequence:
Rule 1: Remove all vowels
Rule 2: Reverse the remaining letters
If the input is 'HELLO', what is the output?
Exam Q 22023Previous Year Pattern
A sorting machine arranges numbers in ascending order and then outputs the middle number. If the input is: 15, 8, 23, 12, 19, what is the output?
Exam Q 32023Previous Year Pattern
A vending machine follows this rule: If the input is even, divide by 2. If the input is odd, multiply by 3 and add 1. What is the output if the input is 7?
Exam Q 42023Previous Year Pattern
In a coding system, each letter is replaced by the number of its position in the alphabet. For example, A=1, B=2, C=3, etc. What is the output for the word 'CAB'?
Exam Q 52023Previous Year Pattern
A machine processes 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 62023Previous Year Pattern
A number system converts input as follows: Add 10, then multiply by 2, then subtract 4. If the input is 5, what is the output?
Exam Q 72023Previous Year Pattern
A sequence follows this pattern:
Input: Take a two-digit number
Step 1: Add 7
Step 2: Multiply by 2
Step 3: Subtract 14
Step 4: Divide by 2
For input 25, what is the output? Also, what is the relationship between input and output?
Exam Q 82023Previous Year Pattern
A data processor follows this algorithm:
Input: A list of numbers [a, b, c, d]
Step 1: Sum all numbers
Step 2: Divide the sum by the count of numbers
Step 3: Subtract this result from each number
Step 4: Sum the absolute values of the results from Step 3
For input [2, 4, 6, 8], what is the final output?
Exam Q 92023Previous Year Pattern
A machine sorts items based on these rules:
- If the item is RED, move it LEFT
- If the item is BLUE, move it RIGHT
- If the item is GREEN, move it UP
- If the item is YELLOW, move it DOWN
- If an item is BOTH RED and BLUE (purple), apply LEFT first, then RIGHT
Starting at position (0,0), an item that is PURPLE moves. What is its final position?
Exam Q 102023Previous Year Pattern
In a coding system, each word is transformed as follows:
- Reverse the word
- Replace each vowel with the next letter in the alphabet
- Capitalize the first letter
What is the output for the word 'APPLE'?
Exam Q 112023Previous Year Pattern
A machine processes input numbers through the following steps:
Step 1: Multiply the number by 3
Step 2: Add 5 to the result
Step 3: Divide by 2
Step 4: Subtract the original number
If the input is 10, what is the final output?
Exam Q 122023Previous Year Pattern
A word transformation system works as follows:
- Count the number of consonants in the word
- Count the number of vowels in the word
- Output: (consonants × 2) - vowels
What is the output for the word 'REASONING'?
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