A professor tells his class that he will give them a surprise examination sometime next week.

For our purposes, an examination is considered a "surprise" if on that day, the class is not 100% sure that they will get an examination. (If they only suspect it, the examination can still be a surprise.)

Having given the class this warning, is it still possible for the professor to give them a surprise examination next week? (Assume that he will not give them an exam if it will not be a surprise.)

Since the professor says it will be next week, and it has to be a total surprise on Friday the students will know that it is on Saturday, on Thursday they will know that is is on Friday and so on... so the test cannot be given, oh i give up! Its a paradox... im not gonna waste my breath explaining it ! :p I think its called the the 'Unexpected hanging Paradox'

Posted by Raveen on 2002-11-22 03:56:29