urgent doubt !! please solve !!

Posted by sanjana26 on Jul 23, 2013; 7:11pm
URL: http://discussion-forum.276.s1.nabble.com/urgent-doubt-please-solve-tp7583745.html

There are 5 letters and 5 directed envelops. the no. of ways in which every letter is in a wrong envelope is??
please explain the answer..