All Exams: Input-Output — Concept Guide + 10 MCQs

This guide covers the complete concept of Input-Output as tested in All Exams 2026, followed by 10 practice MCQs with detailed explanations.

Input-Output — Key Concepts

Understanding Input-Output is essential for scoring well in the Reasoning Ability section of All Exams. This topic appears frequently across all major competitive exams.

Core Concepts

  • Master the fundamental definitions and rules of Input-Output
  • Practice identifying patterns and applying shortcuts
  • Study examples from previous year All Exams papers
  • Time yourself — aim to solve each question in under 1.5 minutes

Shortcut Box

ConceptShortcut / Rule
Basic approachRead the question carefully and identify the type first
Time managementSpend no more than 90 seconds per question
EliminationEliminate obviously wrong options to improve guessing odds

Practice MCQs — Input-Output

Attempt these questions after reading the concept above. Suggested time: 15 minutes.

Q1. In a series 2, 4, 8, 16, __, what is the missing number?

  • A. 24
  • B. 32
  • C. 20
  • D. 18
Explanation: Each number is doubled. 16 × 2 = 32.

Q2. If all roses are flowers and some flowers fade, which conclusion is correct?

  • A. All roses fade
  • B. Some roses may fade
  • C. No roses fade
  • D. All flowers are roses
Explanation: From the given premises, we can only conclude that some roses may fade — not all.

Q3. In a series 2, 4, 8, 16, __, what is the missing number?

  • A. 24
  • B. 32
  • C. 20
  • D. 18
Explanation: Each number is doubled. 16 × 2 = 32.

Q4. If all roses are flowers and some flowers fade, which conclusion is correct?

  • A. All roses fade
  • B. Some roses may fade
  • C. No roses fade
  • D. All flowers are roses
Explanation: From the given premises, we can only conclude that some roses may fade — not all.

Q5. In a series 2, 4, 8, 16, __, what is the missing number?

  • A. 24
  • B. 32
  • C. 20
  • D. 18
Explanation: Each number is doubled. 16 × 2 = 32.

Q6. If all roses are flowers and some flowers fade, which conclusion is correct?

  • A. All roses fade
  • B. Some roses may fade
  • C. No roses fade
  • D. All flowers are roses
Explanation: From the given premises, we can only conclude that some roses may fade — not all.

Q7. In a series 2, 4, 8, 16, __, what is the missing number?

  • A. 24
  • B. 32
  • C. 20
  • D. 18
Explanation: Each number is doubled. 16 × 2 = 32.

Q8. If all roses are flowers and some flowers fade, which conclusion is correct?

  • A. All roses fade
  • B. Some roses may fade
  • C. No roses fade
  • D. All flowers are roses
Explanation: From the given premises, we can only conclude that some roses may fade — not all.

Q9. In a series 2, 4, 8, 16, __, what is the missing number?

  • A. 24
  • B. 32
  • C. 20
  • D. 18
Explanation: Each number is doubled. 16 × 2 = 32.

Q10. If all roses are flowers and some flowers fade, which conclusion is correct?

  • A. All roses fade
  • B. Some roses may fade
  • C. No roses fade
  • D. All flowers are roses
Explanation: From the given premises, we can only conclude that some roses may fade — not all.