Question 1
Amit says: 'Rahul is a liar'
Rahul says: 'Meera is a liar'
Meera says: 'Amit is a truth-teller'
Exactly one person is a liar. What can be concluded?
Let's solve step by step:
Step 1: Assume Meera is a liar.
→ Meera's statement 'Amit is a truth-teller' is FALSE → Amit is a liar.
→ Rahul says 'Meera is a liar' - this is TRUE (since Meera is liar).
→ If Rahul tells truth, then Rahul is truth-teller.
→ Amit (liar) says 'Rahul is a liar' - FALSE (since Rahul is truth) → consistent.
This gives: Amit=L, Rahul=T, Meera=L (two liars, one truth-teller).
Step 2: Assume Meera is a truth-teller.
→ Meera's statement 'Amit is a truth-teller' is TRUE → Amit is truth-teller.
→ Amit (truth) says 'Rahul is a liar' → TRUE → Rahul is liar.
→ Rahul (liar) says 'Meera is a liar' - FALSE (since Meera is truth) → consistent.
This gives: Amit=T, Rahul=L, Meera=T (two truth-tellers, one liar).
Both assignments are valid! This puzzle has two solutions.
To guarantee a unique solution, we add a fourth person:
Meera also says: 'Exactly one of us is a liar'
With this constraint, only Step 2 works (two truth-tellers, one liar).
Therefore, Amit and Meera are truth-tellers, Rahul is a liar.
Step 1: Assume Meera is a liar.
→ Meera's statement 'Amit is a truth-teller' is FALSE → Amit is a liar.
→ Rahul says 'Meera is a liar' - this is TRUE (since Meera is liar).
→ If Rahul tells truth, then Rahul is truth-teller.
→ Amit (liar) says 'Rahul is a liar' - FALSE (since Rahul is truth) → consistent.
This gives: Amit=L, Rahul=T, Meera=L (two liars, one truth-teller).
Step 2: Assume Meera is a truth-teller.
→ Meera's statement 'Amit is a truth-teller' is TRUE → Amit is truth-teller.
→ Amit (truth) says 'Rahul is a liar' → TRUE → Rahul is liar.
→ Rahul (liar) says 'Meera is a liar' - FALSE (since Meera is truth) → consistent.
This gives: Amit=T, Rahul=L, Meera=T (two truth-tellers, one liar).
Both assignments are valid! This puzzle has two solutions.
To guarantee a unique solution, we add a fourth person:
Meera also says: 'Exactly one of us is a liar'
With this constraint, only Step 2 works (two truth-tellers, one liar).
Therefore, Amit and Meera are truth-tellers, Rahul is a liar.