Problem #PRU-5030

Problems Mathematical logic
 10–13  2.0

Problem

In the third room, there are three doors. The statements on them say:

  1. Behind this door there is a trap.

  2. Behind this door there is treasure.

  3. There is a trap behind the second door.

Your guide says: There is treasure behind one of the doors exactly. At most one of the three signs is true - but it is possible all of them are false.
Which door will you open?