CSEET Logical Reasoning – Truth Tellers and Liars Multiple choice questions,answers with explanations.

CSEET Logical Reasoning – Truth Tellers and Liars Multiple choice questions,answers with explanations.  

Q1.

A says, “Both of us are liars.”

B says, “A is telling the truth.”

Who is the truth-teller?

A. A only

B. B only

C. Both A and B

D. None

Answer: B

Explanation:

If A says “Both are liars” and it’s true, A would be a liar (contradiction). So A lies.

If A lies, then B’s statement “A is telling the truth” is false. But that would make B a liar too—contradiction. Hence, B must be telling the truth, and A is lying.

Q2.A says, “B is a liar.”

B says, “A and I are both truth-tellers.”

Who is the liar?

A. A only

B. B only

C. Both

D. None

Answer: B

Explanation:

If B were telling the truth, then A is also a truth-teller. But A says B is a liar → contradiction. Hence B is lying, and A is truthful.

Q3.A says, “B is a liar.”

B says, “We both are liars.”

A. A only lies

B. B only lies

C. Both lie

D. Both tell the truth

Answer: A

Explanation:

If B’s statement “We both are liars” is true, contradiction arises (a liar can’t claim truth). So B is lying → A says “B is liar” → A is telling the truth.

Q4.A says, “Either I am a liar or B is a liar.”

Who is telling the truth?

A. A

B. B

C. Both

D. None

Answer: A

Explanation:

If A were lying, then both would be truth-tellers — contradicts A’s statement. So A tells the truth; hence, B is a liar.

Q5.A says, “B always lies.”

B says, “A and I both tell the truth.”

A. Both lie

B. A tells truth, B lies

C. A lies, B tells truth

D. Both tell truth

Answer: B

Explanation:

If A tells the truth, B always lies. Then B’s claim “Both tell truth” is false — consistent logic.

Q6.

A says, “B is my friend.”

B says, “A always lies.”

If one of them always tells the truth, who is truthful?

A. A

B. B

C. Both

D. None

Answer: B

Explanation:

If B tells the truth → A always lies → “B is my friend” is false → consistent. Hence, B is truthful.

Q7.

A says, “I am a liar.”

Who is telling the truth?

A. A

B. A is lying

C. Both true and false

D. Cannot be determined

Answer: B

Explanation:

If A says “I am a liar” and it’s true → contradiction. Hence, A is lying.

Q8.

A says, “B lies.”

B says, “A lies.”

Who is telling the truth?

A. A

B. B

C. Both

D. None

Answer: D

Explanation:

If A is truthful, B lies; if B lies, A tells truth—perfect loop. Both cannot be truthful simultaneously. The only consistent state is that both are lying.

Q9.

A says, “B and C are liars.”

B says, “Only A is liar.”

C says, “A is liar.”

Who is the truth-teller?

A. A

B. B

C. C

D. None

Answer: B

Explanation:

If B’s statement “Only A is liar” is true → A is liar, C tells truth → fits all statements logically.

Q10.

A says, “C is a liar.”

B says, “A is truthful.”

C says, “B is a liar.”

Who is truthful?

A. A and B

B. B and C

C. A and C

D. A only

Answer: C

Explanation:

If A says “C is liar” and C says “B is liar,” both can be true if B is liar. This makes A and C truthful.

Q11.

A says, “Either B or I lie.”

B says, “A is telling the truth.”

A. Both tell the truth

B. Both lie

C. A tells truth, B lies

D. A lies, B tells truth

Answer: A

Explanation:

If A is truthful → either B or A lies → but if B says A is truthful, there’s no contradiction → both tell truth.

Q12.

A says, “At least one of us is a liar.”

B says, “That’s true.”

A. Both truthful

B. Both liars

C. A truthful, B liar

D. A liar, B truthful

Answer: A

Explanation:

If A says “at least one is liar,” and both are truthful, the statement still holds true logically.

Q13.

A says, “B lies.”

B says, “A and I are both truthful.”

C says, “A is liar.”

Who is the liar?

A. A

B. B

C. C

D. Both A and C

 Answer: B

Explanation:

If B’s statement were true, A also would be truthful—but A says B lies—contradiction. So B lies; A is truthful, C is liar.

Q14.

A says, “Exactly one of us is liar.”

B says, “A is liar.”

A. A is liar

B. B is liar

C. Both lie

D. None

Answer: A

Explanation:

If A is truthful → one liar → B’s statement “A is liar” false → B liar. But then exactly one liar fits → A truthful.

But that creates contradiction in count—hence A lies.

Q15.

A says, “I and B cannot both be liars.”

B says, “A is liar.”

A. A truthful

B. B truthful

C. Both

D. None

Answer: A

Explanation:

If A says they both can’t be liars, and A is truthful → B must be liar → statement consistent.

Quick Tips for CSEET Truth–Lie Questions

Pattern Rule

“I am a liar” Always false (self-contradiction)

Mutual accusations Usually both are lying

“Both are liars” Speaker must be liar

“Either/or” statements Try each case logically

If contradictions appear Only one statement can be true