after the typist writes 12 letters n addresses 12 envelopes she inset into the envelope (1 letter /envelope).what is the probability thatexactly 1 letter is inserted in an improper envelope

• prob=0
  becoz if 1 letter inserted improperly then another letter automatically inserted improperly.
• 11 years agoHelpfull: Yes(7) No(3)
• ans) 0
  atleast two letter inserted wrong not one
• 10 years agoHelpfull: Yes(1) No(0)