Re: Daily question

Posted by Kanika on Mar 30, 2009; 1:08pm
URL: http://discussion-forum.276.s1.nabble.com/Daily-question-tp2328964p2557139.html

D is the killer and B is his accomplice,hence A and c are innocent.If A and c are innocent,their statements should be true.A says "if B is guilty then c must be innocent"-which is true also C says "if B was the killer then D must have had nothing to do with the crime" ,so its contrapositive should also be true that is "if D has something to do with the crime then B is not the killer",which also implies that D is the killer.Also B and D should be telling a lie so the negation of their statements must be true.Hence if B says"if A is innocent ,then c must be guilty" so its negation which is "A  is innocent and c is not guilty" which is true,also the negation of D's statement should be true which is"i am not innocent",which is true as we have proved above that he is the killer.