Question 1

A data processor receives the input 'LOGIC' and applies this rule:
Each letter is replaced by the letter that comes 2 positions after it in the alphabet (A→C, B→D, ..., Y→A, Z→B).

What is the output?

Accepted Answer

This tests consistent application of a shift-based coding rule to multiple elements in sequence.

Question 2

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?

Accepted Answer

This tests sequential operation tracking in input-output problems. Students must apply each step in order without skipping or reversing steps.

Question 3

In a coding system, every letter is replaced by the number of its position in the alphabet (A=1, B=2, C=3, etc.). The output is the sum of all numbers.

What is the output for the word 'CAB'?

Accepted Answer

This tests the ability to apply a consistent coding rule to multiple elements and aggregate the results correctly.

Question 4

A factory receives an input of 100 items. The processing follows these rules:
- Remove 20% of items in Stage 1
- Remove 10 items in Stage 2
- Double the remaining items in Stage 3

How many items are output after all three stages?

Accepted Answer

This tests sequential percentage and arithmetic operations on a quantity, requiring careful tracking of the remaining amount at each stage.

Question 5

A sequence machine takes an input number and applies these rules in order:
1. If the number is even, divide by 2; if odd, multiply by 3 and add 1
2. Repeat the rule from step 1 on the new number
3. Stop when you reach 1

How many times is a rule applied to the input 8 before reaching 1?

Accepted Answer

This tests the ability to track conditional operations and count iterations until a termination condition is met.

Question 6

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 final output is 7, what was the original input?

Accepted Answer

This is a reverse input-output problem. Students must work backwards from the output to find the input by reversing each operation in opposite order.

Question 7

A machine processes input numbers through a sequence of operations. Study the pattern:
Input: 24, 18, 36, 12
Step 1: Add 6 to each number → 30, 24, 42, 18
Step 2: Divide each by 3 → 10, 8, 14, 6
Step 3: Subtract 2 from each → 8, 6, 12, 4
Output: 8, 6, 12, 4

If the input is 48, 32, 16, what will be the output after applying the same three steps?

Accepted Answer

This question tests the ability to identify and apply a consistent sequence of mathematical operations to new input data. The student must trace through each step methodically without skipping or reversing operations.

Question 8

A machine sorts a list of numbers using this algorithm:
Step 1: Identify all even numbers and move them to the front (in original order)
Step 2: Identify all odd numbers and place them after evens (in original order)
Step 3: Multiply each even number by 2 and each odd number by 3

Input: 7, 4, 9, 2, 5, 8

What is the final output?

Accepted Answer

This tests the ability to apply conditional logic (even/odd classification), maintain relative order within groups, and apply differential operations—key input-output reasoning skills.

Question 9

A data processor follows this rule:
- For each number, if it is divisible by 3, divide it by 3
- If it is divisible by 2 (but not 3), divide it by 2
- If it is divisible by both 2 and 3, divide by 6
- If it is divisible by neither, multiply by 2

Input: 12, 15, 8, 9, 7

What is the output?

Accepted Answer

This tests hierarchical conditional logic where the order of conditions matters—a critical reasoning skill for input-output problems involving nested if-then rules.

Question 10

A machine processes a sequence of commands:
- START: Begin with value 0
- ADD X: Add X to current value
- MULTIPLY X: Multiply current value by X
- SUBTRACT X: Subtract X from current value
- RESET: Set value back to 0

Commands: START, ADD 5, MULTIPLY 3, SUBTRACT 7, ADD 4, MULTIPLY 2

What is the final value?

Accepted Answer

This tests sequential state tracking where each operation modifies a running value—a fundamental input-output skill requiring careful order-of-operations adherence.

Question 11

A data transformation system processes pairs of numbers (A, B) as follows:
- Step 1: Calculate A + B
- Step 2: Calculate A × B
- Step 3: If (A + B) > (A × B), output the sum; otherwise, output the product
- Step 4: Subtract 2 from the output of Step 3

If A = 3 and B = 4, what is the final output?

Accepted Answer

This question tests conditional logic based on comparison of two calculated values, requiring careful tracking of intermediate results and correct application of the conditional rule.

Question 12

A number sequence follows this pattern:
- Start with input N
- If N is divisible by 3, divide by 3 and add 5
- If N is not divisible by 3, multiply by 2 and subtract 3
- Repeat the above rule until the result is a single digit (0-9)

Starting with N = 18, what is the final single-digit output?

Accepted Answer

This question tests iterative conditional logic and the ability to track a value through multiple transformations until a stopping condition is met.

Question 13

In a data processing system, numbers are transformed as follows:
- Step 1: Multiply by 3
- Step 2: Add the sum of digits of the result from Step 1
- Step 3: If the result is even, divide by 2; if odd, multiply by 2

Starting with 24, what is the output after all three steps?

Accepted Answer

This question tests sequential numerical transformations with conditional logic. Students must track intermediate results and apply the correct operation based on a condition.

Question 14

A machine processes words through the following rules:

Step 1: Arrange all letters in alphabetical order.
Step 2: Replace each letter with its position number in the English alphabet (A=1, B=2, ... Z=26).
Step 3: Add all the numbers from Step 2 and write the sum.
Step 4: Reverse the digits of the sum obtained in Step 3.

If the input word is 'MEDIA', what will be the final output?

Accepted Answer

Let's trace through each step:

Input: MEDIA

Step 1: Arrange letters alphabetically
M, E, D, I, A → A, D, E, I, M

Step 2: Replace with position numbers
A=1, D=4, E=5, I=9, M=13
Sequence: 1, 4, 5, 9, 13

Step 3: Add all numbers
1 + 4 + 5 + 9 + 13 = 32

Step 4: Reverse the digits of 32
32 reversed = 23

Final Output: 23

Common mistakes:
- Using original word order (MEDIA) instead of alphabetical order - would give 13+5+4+9+1=32 (same sum but incorrect process)
- Forgetting to reverse in Step 4, leaving answer as 32
- Reversing letters instead of the final sum
- Miscounting alphabet positions

RRB NTPC Input-Output

RRB NTPC Input-Output — Past Exam Questions

Input-Output— Rules & Concept

Key Points to Remember

Exam-Specific Tips

Input-Output — Practice Questions

60-Second Revision — Input-Output