Talk:Puzzles/Logic puzzles/False Execution

Some correction needed
English is'n my home language, so i'm not 100% sure i chose the best word. Original Puzzle is in Russian, and it uses "узнать", which can mean both "to be told" and to "to find out". So all i could think of is "get to know". If you know a better solution, feel free to edit. --Divinity 18:52, 17 Jun 2005 (UTC)


 * The first time I heard this puzzle it was in swedish and concerned a tutor telling his pupils about a test. I believe it was formulated something like "you will not know the time of the test the day before the test", which explicitly states that the pupil/prisoner will be lacking the knowledge. This is implicit in the current formulation and could lead to some confusion. But since this is a puzzle, maybe confusion is a good thing. =P -- Grahn 23:06, 28 Jun 2005 (UTC)

I also heard first heard this puzzle in the form of teacher/student/test. It goes like this:

A teacher told his students on friday that a test will be given one of the days next week(monday-friday) and that the students would not know until the day of the test which day it will be.

One clever student reasoned that the test couldn't be given on friday, because the students would know what day the test was if they had not been given the test that day. The student continued with the same logic to reason that the test couldn't be on thursday because as long as friday was ruled out, the students would know the day of the test on wednesday if it were not given that day. In this same way, he reasoned that there could not be a test next week.

To the student's surprise and dismay, the teacher administered the test on tuesday. Explain.