Tina & Meena are twins. One of them lies while the other is truthful. I asked one of them,
“Does Tina lie?” “Yes”, was the answer.
Did I speak to Tina or Meena?
Lets assume both cases
Case 1: If Tina is liar and Meena is truthful
If i ask this question from Meena, answer will be YES in this case and if i ask with Tina, answer will be NO. So in this case i must have asked this from Meena(as YES was the answer).
Case 2: If Tina is truthful and Meena is liar
If i ask this question from Meena answer will be YES in this case(as meena is liar) and Tina should have replied NO, so in this case also i must have asked this question from Meena.