Assertion and Reason

1. What It Is

  • Assertion and Reason (A&R) questions test your ability to analyze statements and understand cause-effect relationships.
  • You are given two statements:
    1. Assertion (A) – a statement or fact.
    2. Reason (R) – an explanation or cause for A.
  • You have to determine:
  • Whether A is true or false
  • Whether R is true or false
  • Whether R correctly explains A

Common in exams because they check logical reasoning and comprehension.

2. How to Approach

  1. Read both statements carefully.
  2. Check Assertion (A) → true or false?
  3. Check Reason (R) → true or false?
  4. Check relationship → if both are true, does R correctly explain A?
  5. Select correct option according to standard pattern.

3. Rules & Key Points

Standard options in exams:

  1. Both A and R are true, and R is correct explanation of A ✅
  2. Both A and R are true, but R is not the correct explanation
  3. A is true, R is false
  4. A is false, R is true

Tips:

  • Always evaluate A first, then R.
  • Even if R is true, it must directly explain A to be correct.
  • If A is false → R cannot be the correct explanation.

4. Tricks & Shortcuts

  1. Highlight keywords in both statements.
  2. Think cause-effect → does R logically lead to A?
  3. If A is factually wrong → correct answer involves A false.
  4. If both A & R are true → verify explanation link carefully.
  5. Ignore extra details in R if they don’t explain A.

5. Types of Assertion & Reason Questions

  1. Fact-based – A and R are factual statements.
  2. Cause-effect – R explains the cause of A.
  3. Conceptual – A is concept, R is principle or reason.
  4. Scientific / Technical – A&R from physics, chemistry, computer science, etc.
  5. Common errors / logic traps – R true but doesn’t explain A.

6. Stepwise Solving Strategy

  1. Read Assertion → true or false?
  2. Read Reason → true or false?
  3. Ask yourself: Does R explain A?
  4. Match with standard options:
    • True/True → explanation correct → option 1
    • True/True → explanation wrong → option 2
    • True/False → option 3
    • False/True → option 4
  5. Eliminate irrelevant options.

7. Easy Practice Questions

1. Fact-based

Assertion (A): The Earth revolves around the Sun.
Reason (R): The Sun is the center of the Solar System.

Solution:

  • A → True
  • R → True
  • R explains A → Yes ✅
  • Answer: Both A & R are true, R is correct explanation of A

2. Cause-Effect

Assertion (A): Metals are good conductors of electricity.
Reason (R): Metals have free electrons that can move easily.

Solution:

  • A → True
  • R → True
  • R explains why metals conduct electricity → Yes ✅
  • Answer: Both A & R true, R correct explanation of A

3. Conceptual

Assertion (A): Water boils at 100°C at sea level.
Reason (R): Boiling point depends on atmospheric pressure.

Solution:

  • A → True
  • R → True
  • R explains A → Yes ✅
  • Answer: Both A & R true, R correct explanation of A

4. False Reason

Assertion (A): The sky appears blue.
Reason (R): The sky reflects the color of the ocean.

Solution:

  • A → True
  • R → False → incorrect reason
  • Answer: A true, R false → option 3

5. True R but not explanation

Assertion (A): Ice floats on water.
Reason (R): Water is a liquid at room temperature.

Solution:

  • A → True
  • R → True, but not the correct explanation
  • Answer: Both true, R is not correct explanation → option 2

8. Difficult Practice Questions

6. Scientific

A: The Sun appears yellow from Earth.
R: The Sun emits yellow light.

Solution:

  • A → True
  • R → False (Sun emits all visible light; yellow is perception)
  • Answer: A true, R false → option 3

7. Conceptual Logic

A: Dividing by zero is undefined.
R: Zero has no reciprocal.

Solution:

  • A → True
  • R → True → correct explanation ✅
  • Answer: Both true, R correct explanation → option 1

8. Computer Science

A: In programming, an array index starts from 0 in C.
R: Arrays store elements in contiguous memory locations.

Solution:

  • A → True
  • R → True, but does not explain why index starts from 0
  • Answer: Both true, R not correct explanation → option 2

9. Logical Trap

A: Steel is stronger than wood.
R: Wood is lighter than steel.

Solution:

  • A → True
  • R → True, but unrelated → does not explain A
  • Answer: Both true, R not explanation → option 2

10. Technical

A: Air has mass.
R: Air exerts pressure on objects.

Solution:

  • A → True
  • R → True, but pressure is not the reason air has mass
  • Answer: Both true, R not correct explanation → option 2

✅ Quick Tips

  1. Always evaluate A first, then R.
  2. Check explanation link, not just truth.
  3. Beware of true R but irrelevant to A.
  4. Eliminate options systematically → 4 options always standard.
  5. Practice with science, reasoning, and general facts → helps recognize patterns.