Three sisters are identical triplets. The oldest by minutes is Sarah, and Sarah always tells anyone the truth. The next oldest is Shreya, and Shreya always will tell anyone a lie. Shirin is the youngest of the three. She sometimes lies and sometimes tells the truth.
Vikram, an old friend of the family's, came over one day and as usual he didn't know who was who, so he asked each of them one question.
Vikram asked the sister that was sitting on the left, "Which sister is in the middle of you three?" and the answer he received was, "Oh, that's Sarah."
Vikram then asked the sister in the middle, "What is your name?" The response given was, "I'm Shirin."
Vikram turned to the sister on the right, then asked, "Who is that in the middle?" The sister then replied, "She is Shreya."
This confused Vikram; he had asked the same question three times and received three different answers.
Who was who?