Briefly

The three sisters

The three sisters

I have three sisters who never recognize their age. When asked about age they always answer the following:

1) Alicia and Beatriz say that one of them is the oldest of the three.
2) One of two, or Carla is the oldest or Alicia is the youngest.

Which is the largest of the three?

Solution

In the first track, if Alicia were the oldest, then in the 2nd track Carla cannot be and Alicia would also be the minor so we reached a contradiction.

Then according to the first clue, the oldest is Beatriz and on the second track Carla can't be the biggest so Alicia is the youngest and Carla is the middle one.