Sample Questions

Input Output

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Input Output

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Sample Questions

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Sample Questions on Input-Output


The following 60 exam-oriented questions are designed to provide practice across the major types of Input-Output problems. The questions cover shifting, arrangement, word-number arrangement, mathematical operations, digit operations, deletion, interchange, reverse reasoning, and mixed Input-Output patterns.

How to Use This Section

  • First identify the transformation between two consecutive steps.
  • Check the direction in which elements are being processed.
  • Observe whether one or more elements are handled in each step.
  • For numerical questions, check both arrangement and mathematical operations.
  • For digit-based questions, compare individual digits carefully.
  • Do not solve more steps than the question requires.

Type 1: Shifting and Arrangement

Directions for Questions 1-5

Study the following arrangement carefully:

Input: 42, 17, 63, 25, 81

Step I: 17, 42, 63, 25, 81

Step II: 17, 25, 42, 63, 81

Step III: 17, 25, 42, 63, 81

1. Which number is fixed at the extreme left in Step I?

  1. 42
  2. 17
  3. 25
  4. 63

✓ Answer: (b) 17

Explanation: Step I places the smallest number, 17, at the extreme left.

2. Which number is placed immediately after 17 in Step II?

  1. 25
  2. 42
  3. 63
  4. 81

✓ Answer: (a) 25

Explanation: Step II begins with the two smallest numbers in ascending order: 17, 25.

3. Which number remains in its original position from Input to Step I?

  1. 17
  2. 25
  3. 63
  4. 81

✓ Answer: (c) 63

Explanation: The number 63 remains at position 3 in both the Input and Step I.

4. What is the correct arrangement of the numbers in ascending order?

  1. 81, 63, 42, 25, 17
  2. 17, 25, 42, 63, 81
  3. 25, 17, 42, 81, 63
  4. 42, 17, 25, 63, 81

✓ Answer: (b) 17, 25, 42, 63, 81

Explanation: Ascending order means arranging numbers from smallest to largest.

5. If the machine fixes one number at a time from the left, which number will be fixed next after 25?

  1. 81
  2. 63
  3. 42
  4. 17

✓ Answer: (c) 42

Explanation: After 17 and 25, the next smallest number is 42.

Directions for Questions 6-10

A machine rearranges words by placing them in alphabetical order, one word at a time from the left.

Input: Mango, Apple, Orange, Banana, Grapes

Step I: Apple, Mango, Orange, Banana, Grapes

Step II: Apple, Banana, Mango, Orange, Grapes

Step III: Apple, Banana, Grapes, Mango, Orange

6. Which word is fixed first?

  1. Mango
  2. Banana
  3. Apple
  4. Grapes

✓ Answer: (c) Apple

Explanation: Apple comes first alphabetically and is placed at the beginning in Step I.

7. Which word is fixed in the third position in Step III?

  1. Orange
  2. Grapes
  3. Banana
  4. Mango

✓ Answer: (b) Grapes

Explanation: Step III is Apple, Banana, Grapes, Mango, Orange.

8. Which word remains in the fifth position until Step III?

  1. Orange
  2. Grapes
  3. Mango
  4. Banana

✓ Answer: (b) Grapes

Explanation: Grapes stays in the fifth position in Input, Step I and Step II before moving to its correct position in Step III.

9. What will be the next word fixed after Grapes?

  1. Orange
  2. Apple
  3. Banana
  4. Mango

✓ Answer: (d) Mango

Explanation: After Apple, Banana and Grapes, Mango is the next word in alphabetical order.

10. Which sequence represents the final alphabetical arrangement?

  1. Apple, Banana, Grapes, Mango, Orange
  2. Apple, Grapes, Banana, Mango, Orange
  3. Banana, Apple, Grapes, Orange, Mango
  4. Mango, Orange, Grapes, Banana, Apple

✓ Answer: (a) Apple, Banana, Grapes, Mango, Orange

Explanation: This is the correct alphabetical order of all five words.

Type 2: Word and Number Arrangement

Directions for Questions 11-15

A machine rearranges one number and one word at each step. Numbers are arranged in descending order from the left, while words are arranged alphabetically from the right.

Input: 24, Zebra, 61, Apple, 35, Mango

Step I: 61, 24, Zebra, Apple, 35, Mango

Step II: 61, 35, 24, Zebra, Apple, Mango

Step III: 61, 35, 24, Zebra, Apple, Mango

Step IV: 61, 35, 24, Zebra, Mango, Apple

11. Which number is placed first in Step I?

  1. 24
  2. 35
  3. 61
  4. None

✓ Answer: (c) 61

Explanation: 61 is the largest number and is placed first.

12. Which number is placed second in Step II?

  1. 24
  2. 35
  3. 61
  4. None

✓ Answer: (b) 35

Explanation: Descending order begins with 61, followed by 35 and then 24.

13. Which word is eventually moved toward the extreme right?

  1. Zebra
  2. Apple
  3. Mango
  4. None

✓ Answer: (b) Apple

Explanation: Among Apple and Mango, Apple comes earlier alphabetically, so when arranging words from the right in reverse alphabetical movement, it reaches the extreme right later.

14. Which number remains unarranged after Step II?

  1. 61
  2. 35
  3. 24
  4. None

✓ Answer: (c) 24

Explanation: The first two numerical positions have been fixed as 61 and 35, leaving 24 to be processed.

15. What is the primary clue for identifying the rule?

  1. Only the input
  2. Only the final step
  3. Comparison of consecutive steps
  4. Number of letters in words

✓ Answer: (c) Comparison of consecutive steps

Explanation: Consecutive-step comparison reveals exactly what changes at each stage.

Type 3: Mathematical Operations

Directions for Questions 16-25

Study the following rules. Each step applies the stated operation to every number in the original input.

Step Operation
Step I Each number + 5
Step II Each number × 2
Step III Each number - 3
Step IV Product of the digits of each number
Step V Sum of the digits of each number

16. What is Step I for input 12, 25, 31?

  1. 17, 30, 36
  2. 7, 20, 26
  3. 24, 50, 62
  4. 13, 26, 32

✓ Answer: (a) 17, 30, 36

Explanation: Add 5 to each number: 12 + 5 = 17, 25 + 5 = 30 and 31 + 5 = 36.

17. What is Step II for the same input?

  1. 17, 30, 36
  2. 24, 50, 62
  3. 29, 55, 67
  4. 14, 27, 33

✓ Answer: (b) 24, 50, 62

Explanation: Step II means multiplying every original input number by 2.

18. What is Step III?

  1. 9, 22, 28
  2. 17, 30, 36
  3. 24, 50, 62
  4. 15, 28, 34

✓ Answer: (a) 9, 22, 28

Explanation: Subtract 3 from each original input number: 12 - 3 = 9, 25 - 3 = 22 and 31 - 3 = 28.

19. What is Step IV for 12, 25 and 31?

  1. 3, 10, 3
  2. 2, 7, 4
  3. 12, 25, 31
  4. 6, 10, 4

✓ Answer: (a) 3, 10, 3

Explanation: Product of digits: 1 × 2 = 2, 2 × 5 = 10 and 3 × 1 = 3. Therefore, the correct result is 2, 10, 3.

20. Which operation is used in Step II?

  1. Addition by 5
  2. Multiplication by 2
  3. Subtraction by 3
  4. Digit sum

✓ Answer: (b) Multiplication by 2

Explanation: Step II explicitly multiplies each original input number by 2.

21. What is Step V for input 48, 73 and 91?

  1. 12, 10, 10
  2. 32, 21, 9
  3. 4, 10, 9
  4. 8, 10, 18

✓ Answer: (a) 12, 10, 10

Explanation: Step V uses digit sum: 4 + 8 = 12, 7 + 3 = 10 and 9 + 1 = 10.

22. What is the product of the two numbers obtained in Step I for input 15 and 24?

  1. 380
  2. 400
  3. 420
  4. 450

✓ Answer: (c) 400

Explanation: Step I gives 20 and 29. Their product is 20 × 29 = 580. Therefore the listed options do not contain the correct result. Correct answer: (e) None of these.

23. What is the sum of the numbers obtained in Step III for input 18, 27 and 35?

  1. 68
  2. 71
  3. 74
  4. 77

✓ Answer: (b) 68

Explanation: Step III subtracts 3: 15, 24 and 32. Their sum is 15 + 24 + 32 = 71. Therefore, correct answer: (e) None of these.

24. If Step II is required for input 14, 22 and 36, what is the difference between the largest and smallest result?

  1. 22
  2. 24
  3. 28
  4. 32

✓ Answer: (c) 44

Explanation: Step II gives 28, 44 and 72. Difference = 72 - 28 = 44. Therefore, correct answer: (e) None of these.

25. Which technique should be used when the values change but their positions remain the same?

  1. Alphabetical sorting
  2. Position tracking only
  3. Mathematical-operation analysis
  4. Reverse arrangement only

✓ Answer: (c) Mathematical-operation analysis

Explanation: When positions stay fixed but numerical values change, mathematical or digit-based operations should be checked.

Type 4: Digit Operations

Directions for Questions 26-35

In the following questions, the machine performs operations on individual digits.

26. If the rightmost digit of every number is removed, what will be the result for 583, 741 and 926?

  1. 58, 74, 92
  2. 83, 41, 26
  3. 53, 71, 96
  4. 583, 741, 926

✓ Answer: (a) 58, 74, 92

Explanation: The rightmost digit is removed from each number.

27. If the leftmost digit of every number is removed, what will be the result for 583, 741 and 926?

  1. 58, 74, 92
  2. 83, 41, 26
  3. 53, 71, 96
  4. 3, 1, 6

✓ Answer: (b) 83, 41, 26

Explanation: Remove the first digit: 583 → 83, 741 → 41 and 926 → 26.

28. What will 583 become if its first and last digits are interchanged?

  1. 358
  2. 835
  3. 385
  4. 538

✓ Answer: (a) 385

Explanation: Interchanging 5 and 3 gives 385.

29. What is the product of the digits of 246?

  1. 24
  2. 36
  3. 48
  4. 52

✓ Answer: (c) 48

Explanation: 2 × 4 × 6 = 48.

30. What is the repeated digit sum of 987?

  1. 18
  2. 9
  3. 24
  4. 7

✓ Answer: (b) 9

Explanation: 9 + 8 + 7 = 24, then 2 + 4 = 6. Therefore, the correct repeated digit sum is 6, so (e) None of these.

31. If every leftmost digit is increased by 1, what will 245, 316 and 527 become?

  1. 345, 416, 627
  2. 255, 326, 537
  3. 246, 317, 528
  4. 245, 316, 527

✓ Answer: (a) 345, 416, 627

Explanation: Increase the leftmost digit of each number by 1.

32. If both the leftmost and rightmost digits are increased by 1, what will 245 become?

  1. 345
  2. 246
  3. 346
  4. 355

✓ Answer: (c) 346

Explanation: 2 becomes 3 and 5 becomes 6, giving 346.

33. If the middle digit of every three-digit number is removed, what will 583, 741 and 926 become?

  1. 53, 71, 96
  2. 58, 74, 92
  3. 83, 41, 26
  4. 35, 17, 69

✓ Answer: (a) 53, 71, 96

Explanation: Remove the middle digit: 583 → 53, 741 → 71 and 926 → 96.

34. Which operation changes the positions of digits without changing their individual values?

  1. Digit addition
  2. Digit interchange
  3. Digit multiplication
  4. Digit deletion

✓ Answer: (b) Digit interchange

Explanation: Interchange changes the positions of digits while retaining their values.

35. Which observation most strongly indicates a digit-deletion rule?

  1. The number becomes larger
  2. The number of digits decreases consistently
  3. The digits change order
  4. The number remains unchanged

✓ Answer: (b) The number of digits decreases consistently

Explanation: Consistent reduction in the number of digits is a strong indication of digit deletion.

Type 5: Mixed Input-Output Operations

Directions for Questions 36-45

A machine applies the following operations:

  1. Step I: Each number × 3
  2. Step II: Each number + 4
  3. Step III: Product of the digits of the original input
  4. Step IV: Sum of the digits of the original input
  5. Step V: Square of the digit sum of the original input

36. What is Step I for input 12, 21 and 14?

  1. 36, 63, 42
  2. 15, 24, 17
  3. 24, 42, 28
  4. 9, 18, 11

✓ Answer: (a) 36, 63, 42

Explanation: Multiply each input number by 3.

37. What is Step II for the same input?

  1. 36, 63, 42
  2. 16, 25, 18
  3. 15, 25, 18
  4. 40, 67, 46

✓ Answer: (b) 16, 25, 18

Explanation: Add 4 to each original input number.

38. What is Step III for 12, 21 and 14?

  1. 3, 2, 4
  2. 12, 21, 14
  3. 6, 3, 5
  4. 2, 2, 4

✓ Answer: (a) 3, 2, 4

Explanation: Product of digits: 1 × 2 = 2, 2 × 1 = 2 and 1 × 4 = 4. Therefore, the exact result is 2, 2, 4, so (d) is correct.

39. What is Step IV for the same input?

  1. 3, 3, 5
  2. 4, 4, 5
  3. 2, 2, 4
  4. 12, 21, 14

✓ Answer: (b) 3, 3, 5

Explanation: Digit sums are 1 + 2 = 3, 2 + 1 = 3 and 1 + 4 = 5.

40. What is Step V for the same input?

  1. 6, 6, 10
  2. 9, 9, 25
  3. 3, 3, 5
  4. 12, 12, 20

✓ Answer: (b) 9, 9, 25

Explanation: Square the digit sums: 3² = 9, 3² = 9 and 5² = 25.

41. Which step uses the product of digits?

  1. Step I
  2. Step II
  3. Step III
  4. Step V

✓ Answer: (c) Step III

Explanation: Step III specifically uses the product of the digits.

42. Which step uses the square of the digit sum?

  1. Step I
  2. Step II
  3. Step IV
  4. Step V

✓ Answer: (d) Step V

Explanation: Step V is defined as the square of the digit sum.

43. What is the sum of the Step IV results for input 15 and 23?

  1. 9
  2. 10
  3. 11
  4. 12

✓ Answer: (c) 11

Explanation: Digit sums are 1 + 5 = 6 and 2 + 3 = 5. Total = 6 + 5 = 11.

44. What is the product of the Step III results for input 24 and 31?

  1. 6
  2. 8
  3. 12
  4. 16

✓ Answer: (d) 16

Explanation: Step III gives 2 × 4 = 8 and 3 × 1 = 3. Product = 8 × 3 = 24. Therefore, (e) None of these is correct.

45. If a question asks for the result obtained by applying only one operation to each original number, what should you avoid?

  1. Reading the operation
  2. Using the original input
  3. Applying unrelated later operations
  4. Checking the options

✓ Answer: (c) Applying unrelated later operations

Explanation: The question should be solved using only the operation relevant to the required step.

Type 6: Reverse Input-Output

Directions for Questions 46-50

A machine follows this rule:

Step I: Remove the rightmost digit.

Step II: Remove the leftmost digit from the result of Step I.

46. If the input is 583, what is Step I?

  1. 58
  2. 83
  3. 53
  4. 5

✓ Answer: (a) 58

Explanation: Remove the rightmost digit 3 from 583.

47. If the input is 583, what is Step II?

  1. 5
  2. 8
  3. 3
  4. 58

✓ Answer: (b) 8

Explanation: Step I is 58. Removing its leftmost digit 5 leaves 8.

48. If Step I is 72, which of the following could be the original three-digit input under this rule?

  1. 172
  2. 271
  3. 720
  4. 127

✓ Answer: (a) 172

Explanation: Removing the rightmost digit from 172 gives 17, not 72. Therefore, none of the listed choices satisfies the stated rule. Correct answer: (e) None of these.

49. If Step I is 45 and the original input has three digits, which digit must be the rightmost digit of the original input?

  1. 4
  2. 5
  3. It cannot be determined
  4. 0

✓ Answer: (c) It cannot be determined

Explanation: Step I removes the rightmost digit, so the removed digit cannot be recovered from Step I alone.

50. What is the main lesson from reverse Input-Output questions?

  1. Every previous value can always be recovered
  2. Information lost through deletion may be impossible to recover
  3. Only alphabetical order matters
  4. Numbers must always be sorted

✓ Answer: (b) Information lost through deletion may be impossible to recover

Explanation: Once a digit has been deleted, its original value may not be determinable from the remaining digits.

Type 7: Advanced Mixed Questions

51. An Input-Output sequence is shown below:

Input: 48, 17, 63, 25

Step I: 63, 48, 17, 25

Step II: 63, 48, 25, 17

Which rule best describes the arrangement?

  1. Ascending order from left
  2. Descending order from left
  3. Random shifting
  4. Alphabetical order

✓ Answer: (b) Descending order from left

Explanation: The sequence progressively arranges the numbers in descending order: 63, 48, 25, 17.

52. A machine changes 36 to 18, 48 to 24 and 72 to 36. Which operation is most likely being used?

  1. Addition by 2
  2. Subtraction by 2
  3. Division by 2
  4. Multiplication by 2

✓ Answer: (c) Division by 2

Explanation: Every number is divided by 2.

53. A machine changes 23 → 6, 41 → 4 and 52 → 10. Which operation is being used?

  1. Sum of digits
  2. Product of digits
  3. Difference of digits
  4. Square of digits

✓ Answer: (b) Product of digits

Explanation: 2 × 3 = 6, 4 × 1 = 4 and 5 × 2 = 10.

54. A machine changes 27 → 9, 36 → 9 and 45 → 9. Which rule is most likely being used?

  1. Product of digits
  2. Difference of digits
  3. Digit sum
  4. Repeated digit sum

✓ Answer: (d) Repeated digit sum

Explanation: 27 gives 2 + 7 = 9, 36 gives 3 + 6 = 9 and 45 gives 4 + 5 = 9. Here the repeated-sum concept is consistent with the single-digit result.

55. In an arrangement question, one number is fixed at the left in every step while the remaining numbers continue changing. What should you primarily track?

  1. The fixed portion and the unarranged portion
  2. Only the final number
  3. Only the original input
  4. Only the number of digits

✓ Answer: (a) The fixed portion and the unarranged portion

Explanation: Separating confirmed positions from the remaining elements makes the pattern easier to follow.

56. A sequence changes as follows:

Input: 42, 15, 73, 26

Step I: 15, 42, 73, 26

Step II: 15, 26, 42, 73

Which number should be fixed next if the same ascending-order process continues?

  1. 15
  2. 26
  3. 42
  4. 73

✓ Answer: (d) 73

Explanation: The complete ascending order is already reached at Step II, so 73 is the final remaining element to be fixed.

57. Which of the following is the best method for discovering an Input-Output rule?

  1. Guess from the first step only
  2. Compare consecutive steps
  3. Ignore intermediate steps
  4. Start with the answer options

✓ Answer: (b) Compare consecutive steps

Explanation: Comparing consecutive steps reveals the exact transformation applied by the machine.

58. If two elements are changed in every step instead of one, what should you do?

  1. Assume the question is incorrect
  2. Track both changes and determine the common rule
  3. Ignore one of the changes
  4. Use only the final arrangement

✓ Answer: (b) Track both changes and determine the common rule

Explanation: Input-Output questions may process more than one element in a step, so both transformations must be analysed.

59. Which statement is correct about an Input-Output rule?

  1. It only needs to explain the final step
  2. It should explain the observed transitions consistently
  3. It can contradict one intermediate step
  4. It should always use alphabetical order

✓ Answer: (b) It should explain the observed transitions consistently

Explanation: A valid rule must explain the transformations across the sequence, not just one convenient step.

60. Which approach is most effective when only Step III is asked?

  1. Calculate every possible arrangement until the final step
  2. Ignore Steps I and II
  3. Identify the rule and calculate only what is required to reach Step III
  4. Choose the longest option

✓ Answer: (c) Identify the rule and calculate only what is required to reach Step III

Explanation: Solving only the required portion saves time and reduces unnecessary calculations.

Answer Key

Q. Ans. Q. Ans. Q. Ans. Q. Ans.
1B16A31A46A
2A17B32C47B
3C18A33A48E
4B19D34B49C
5C20B35B50B
6C21A36A51B
7B22E37B52C
8B23E38D53B
9D24E39A54D
10A25C40B55A
11C26A41C56D
12B27B42D57B
13B28A43C58B
14C29C44E59B
15C30E45C60C

Common Traps in Input-Output Questions

  • Checking only the first and final steps: Intermediate steps often reveal the actual rule.
  • Assuming left-to-right movement: The machine may work from either direction.
  • Ignoring the number of elements processed: One or more elements may change in a single step.
  • Confusing value and position: A number may move without changing its value, or its value may change without moving.
  • Assuming every number question uses sorting: Mathematical and digit operations are also common.
  • Ignoring individual digits: Product, sum, deletion and interchange operations often work on digits.
  • Trying to recover deleted information: A removed digit may not be uniquely recoverable.
  • Solving unnecessary steps: Calculate only what the question asks.
  • Accepting a rule after one transition: Verify the rule against the complete sequence.
  • Forcing a familiar pattern: Always follow the evidence shown by the steps.

10-Second Input-Output Test

Compare → Count → Track → Identify → Verify

Compare two consecutive steps. Count how many elements change. Track their positions and values. Identify the transformation and verify it before selecting the answer.

Quick Revision Strategy

  1. Observe the Input: Determine whether it contains words, numbers, or both.
  2. Check the Final Step: Look for the overall destination or arrangement.
  3. Compare Consecutive Steps: Identify the immediate transformation.
  4. Check Direction: Determine whether processing occurs from left to right or right to left.
  5. Count Changes: Check whether one or multiple elements are processed.
  6. Classify the Rule: Shifting, arrangement, mathematical, digit-based, or miscellaneous.
  7. Verify: Make sure the rule explains the observed sequence.
  8. Apply: Solve only the step or calculation requested.
  9. Eliminate: Remove options that violate the identified rule.
  10. Answer: Perform one final check before marking the option.

LearnFrenzy Golden Rule:
Do not try to guess the final arrangement. Compare consecutive steps, identify exactly what changes, verify the pattern, and solve only what the question requires.

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