A wealthy wise old woman feared that her daughter was lazy and, as a result, rather stupid. When the old woman died, her will stipulated that her assets were to be liquidated and a check was to be written for the full amount.
The check was to be placed in one of three envelopes. The other two envelopes would contain a blank piece of paper. If the daughter could determine from the writing on the envelope which envelope contained the check, she would inherit her mother’s fortune. Otherwise, the fortune would go to the old woman’s favorite charity for animals.
The daughter was not allowed to touch the envelopes. Her decision had to be made based on the writing on the envelopes. The daughter was told that only one envelope had a true statement and that the other two statements were false.
The envelopes had the following writing:
1. This envelope does not have the check.
2. This envelope has the check.
3. The second envelope does not have the check.
Which envelope should the daughter pick?
The daughter should pick envelope 1. Statements 1 and 2 are false, and the only true statement is statement 3.
If the check was in envelope 1, that would make statement 1 and statement 2 false and statement 3 would be the only true statement.
If the check was in envelope 2, both statements 1 and 2 would be true.
If the check was in envelope 3, both statements 1 and 3 wouldbe true.