Assertion and Reason Questions Logical Reasoning (original) (raw)

Last Updated : 20 Apr, 2026

Assertion and Reason questions test your ability to evaluate a statement and the explanation given for it.

Key Components:

In general, an assertion and reason are an affirmation, a declaration, or a strong statement. Normally, in logical reasoning, assertions have reasons.

In simple words, Assertion is the statement of fact and Reason is the explanation for the given assertion.

Assertion and Reasoning questions test the ability to evaluate two statements, an **Assertion (A) and a **Reason (R), and determine their logical relationship.

These questions typically follow five standard answer options:

**Option A: Both the Assertion and Reason are true, and the Reason is the correct and direct explanation of the Assertion.

**Example: A: Metal objects expand when heated. R: Heating increases the kinetic energy of metal atoms causing them to vibrate more and occupy more space.

**Option B: Both the Assertion and Reason are true, but the Reason is not the correct explanation of the Assertion; the two statements are independent of each other.

**Example: A: Plants conduct photosynthesis. R: Photosynthesis is essential for plant growth.

**Option C: The Assertion is true, but the Reason is false or incorrect.

**Example: A: Sound cannot travel through vacuum. R: Sound travels through vacuum at a very slow speed.

**Option D: The Assertion is false, but the Reason is true.

**Example: A: The Moon revolves around the Sun directly. R: The Moon is a natural satellite that orbits the Earth.

**Option E: Both the Assertion and the Reason are completely false.

**Example: A: Humans can survive without oxygen by breathing nitrogen. R: Nitrogen provides energy required for cellular respiration.

How To Solve Assertion And Reasoning Questions?

The following methods help you solve assertion and reasoning questions efficiently:

**1. Understand the Question Clearly:

Carefully read the question and understand what is being asked. Identify the meaning of both the Assertion (A) and Reason (R) before attempting to solve.

**2. Evaluate Each Statement Individually:

Analyze the Assertion and Reason separately. Determine whether each statement is true or false without linking them initially.

**3. Check the Logical Connection:

If both statements are true, examine whether the Reason correctly explains the Assertion.

**Things To Consider While Solving Assertion And Reasoning Problems

Here are some things to consider while addressing assertion and reasoning questions:

**1. Understand the Statements
Carefully read both the Assertion (A) and Reason (R). Identify the key idea of each statement.

**2. Evaluate Assertion Independently
Check whether the Assertion is true or false using your knowledge. Do not consider the Reason at this stage.

**3. Evaluate Reason Independently
Now examine the Reason separately and decide whether it is true or false.

**4. Check Logical Connection
If both statements are true, verify whether the Reason correctly explains the Assertion.

**5. Check Relevance
Ensure the Reason is directly related to the Assertion. A true but unrelated reason is not a correct explanation.

**6. Avoid Assumptions
Do not add extra information. Base your answer only on the given statements.

**7. Apply Concepts (if needed)
Use relevant principles or theories to verify the statements, especially in scientific questions.

**8. Analyze Cause–Effect Relationship
Check whether the Reason shows a clear cause-and-effect link with the Assertion.

Solved Examples

**Example 1:

**Assertion (A): Birds have feathers.
**Reason (R): Feathers help birds to fly.

**Options:

**Answer: A - Both A and R are true, and R is the correct explanation of A.

**Explanation: Both the assertion and reason are true. Feathers indeed help birds fly, as they provide lift and control during flight.

**Example 2:

**Assertion (A): The Earth orbits the Sun.
**Reason (R): The Sun is much larger than the Earth.

**Options:

**Answer: A - B - Both A and R are true, but R is NOT the correct explanation of A.

**Explanation: Earth orbits the Sun due to gravitational force, not just because the Sun is larger.

**Example 3:

**Assertion (A): Plants conduct photosynthesis.
**Reason (R): Photosynthesis is essential for plant growth.

**Options:

**Answer: B - Both A and R are true, but R is NOT the correct explanation of A.

**Explanation: Plants do photosynthesis, and it is important for growth, but the reason does not explain _why plants conduct photosynthesis.

**Example 4:

**Assertion (A): Water boils at 100°C at sea level.
**Reason (R): Atmospheric pressure affects the boiling point of water.

Options:

**Answer: A - Both A and R are true, and R is the correct explanation of A.

**Explanation: Both the assertion and reason are true. The boiling point of water varies with changes in atmospheric pressure, and at sea level, it boils at 100 degrees Celsius.

**Example 5:

**Assertion (A): Oxygen is necessary for combustion.
**Reason (R): Combustion is a chemical reaction involving the release of energy.

Options:

**Answer: A - Both A and R are true, but R is NOT the correct explanation of A.

**Explanation: Both the assertion and reason are true. Oxygen is a crucial component of combustion, which is indeed a chemical reaction releasing energy.

**Example 6:

**Assertion (A): Metal objects expand when heated.
**Reason (R): Heating increases the kinetic energy of metal atoms.

Options:

**Answer: A - Both A and R are true, and R is the correct explanation of A.

**Explanation: Both the assertion and reason are true. Heating metal objects increases the kinetic energy of their atoms, causing expansion.

**Example 7:

**Assertion (A): The Moon has gravitational pull.
**Reason (R): Gravity is a fundamental force of nature.

Options:

**Answer: B - Both A and R are true, but R is NOT the correct explanation of A.

**Explanation: Both the assertion and reason are true. The Moon's gravitational pull is due to the fundamental force of gravity.

**Example 8:

**Assertion (A): Sound travels faster in solids than in gases.
**Reason (R): Solids have a higher density than gases.

Options:

**Answer: A - Both A and R are true, and R is the correct explanation of A.

**Explanation: Both the assertion and reason are true. Sound travels faster in denser materials, such as solids, due to the closer arrangement of particles.

**Example 9:

**Assertion (A): Adding salt to water lowers its freezing point.
**Reason (R): Salt disrupts the formation of ice crystals.

Options:

**Answer: A - Both A and R are true, and R is the correct explanation of A.

**Explanation: Both the assertion and reason are true. Adding salt lowers the freezing point of water by interfering with the formation of ice crystals.

**Example 10:

**Assertion (A): Human beings require oxygen to survive.
**Reason (R): Oxygen is essential for cellular respiration.

Options:

**Answer: A - Both A and R are true, and R is the correct explanation of A.

**Explanation: Both the assertion and reason are true. Humans require oxygen for cellular respiration, a process that produces energy necessary for survival.