Assertion and Reason Reasoning: Rules, Tricks and Solved Questions with Answers for SSC CGL, CHSL

In an assertion and reason question, two statements are given: an Assertion (A) and a Reason (R). You must decide whether each one is true, and whether R really explains A. The question looks tricky, but a 3-step check solves it in 30 seconds. These assertion and reason reasoning tricks for SSC give the five standard options, the method and solved examples.

The Five Standard Options

The order of the options can differ in different papers, so read the option text, not only the letter.

Three-Step Method

1. Check the Assertion (A) alone. Is it true or false?
2. Check the Reason (R) alone. Is it true or false?
3. If both are true, put the word "because" between them: "A because R". If this sentence is logical, then R explains A.

Solved Examples

Example 1. A: The sky appears blue. R: Blue light is scattered more than the other colours by the atmosphere.
Both are true, and "the sky is blue because blue light is scattered more" is correct. R explains A.

Example 2. A: The Earth has seasons. R: The axis of the Earth is tilted.
Both are true and the tilt is the cause of the seasons. R explains A.

Example 3. A: Water boils at 100°C at sea level. R: Mercury is a liquid metal.
Both are true, but one is not the reason of the other. Both true, R does not explain A.

Example 4. A: The Sun rises in the west. R: The Earth rotates from west to east.
A is false (the Sun rises in the east), and R is true. A is false, R is true.

Example 5. A: Ice floats on water. R: Ice is denser than water.
A is true, but R is false (ice is less dense). A is true, R is false.

Example 6. A: The Earth is flat. R: The Sun revolves around the Earth.
Both are false. Both A and R are false.

Tips

• Never mark "R explains A" only because both are true. Use the "because" test.
• Words like always, never, only and all in a statement make it false in most cases.
• Use general knowledge of science, geography and polity to check the facts.
• Check the facts first. The relation comes later.

Quick Tips

• Check A, then R, and then the link.
• Use the "because" test to see if R explains A.
• Both true does not mean R explains A.
• Be careful with extreme words like always and never.

Quick Revision Points

• There are five standard options in assertion and reason.
• First check the facts of A and R separately.
• Use "A because R" to test the link.
• If A is false and R is true, mark that option.
• If both are false, mark the last option.

Practice Questions With Answers

1. A: The Earth has seasons. R: The axis of the Earth is tilted. Choose the correct option.
   Answer: Both are true and R explains A
2. A: The Sun rises in the west. R: The Earth rotates from west to east. Choose the correct option.
   Answer: A is false and R is true
3. A: Ice floats on water. R: Ice is denser than water. Choose the correct option.
   Answer: A is true and R is false
4. A: The Earth is flat. R: The Sun revolves around the Earth. Choose the correct option.
   Answer: Both are false
5. A: Water boils at 100°C at sea level. R: Mercury is a liquid metal. Choose the correct option.
   Answer: Both are true but R does not explain A
6. A: Plants make food by photosynthesis. R: Photosynthesis needs sunlight. Choose the correct option.
   Answer: Both are true and R explains A (in the sense that sunlight is needed)
7. A: India is in Asia. R: Asia is the largest continent. Choose the correct option.
   Answer: Both are true but R does not explain A
8. A: The Moon is a planet. R: The Moon revolves around the Earth. Choose the correct option.
   Answer: A is false and R is true
9. What is the test to see if R explains A?
   Answer: The "because" test: say A because R
10. What should you check first in an assertion and reason question?
    Answer: Whether A and R are true or false separately

How to Practise This Chapter

Practise 10 questions every day and write the steps on paper. Then attempt timed sets from our practice papers and the previous year papers page. See all topics on the Logical Reasoning notes page and the next topic Statement and Inference. Also read the Reasoning notes.

Frequently Asked Questions

What is assertion and reason in reasoning?

It is a question with two statements, an assertion and a reason, in which you decide if each is true and if the reason explains the assertion.

How many options are there in assertion and reason?

There are five standard options.

How do I check if R explains A?

Say "A because R". If the sentence is correct, R explains A.

Can both A and R be true without a link?

Yes. Both can be true facts, but not related as cause and effect.

What if A is false and R is true?

Then mark the option "A is false but R is true".

What if both statements are false?

Then mark the option "both are false".

Is general knowledge needed?

Yes. Many questions use facts of science, geography and polity.

Is this topic asked in SSC exams?

It is asked in some SSC and other competitive exams as a part of logical reasoning.

How much time should I take?

About 30 seconds.

What are the common mistakes?

Marking "R explains A" because both are true, and not checking the link.

How can I practise this topic?

Solve 10 questions daily and revise the basic science and geography facts.

What do the words always and never show?

They usually make a statement false, because exceptions exist.