after the typist writes 40 letters and addresses 40 envelopes,she inserts the letters randomly into the envelopes(1 letter per envelope).what is the probability that exactly 1 letter is inserted in an improper envelope?

• zero will be the answer .. because u cannot insert only one letter improperly ... if one is inserted wrongly thn another letter should also be inserted in wrong cover ... its simple logic .. no need for going in propability topic :-)
• 13 years agoHelpfull: Yes(45) No(0)
• according to question only one letter is in an improper envelope,,,
  it is impossible ,,,,
  bcoz if 39 letters are in correct envelope then..
  last letter will be obviously in right envelope...
  
  
  so answer is "0"
• 13 years agoHelpfull: Yes(13) No(1)
• definetly ans z 0.
• 13 years agoHelpfull: Yes(3) No(0)
• req probability is pi*r^2/2pi*R=0.5
• 13 years agoHelpfull: Yes(1) No(13)
• req probability is pi*r^2/2pi*R=0.5
• 13 years agoHelpfull: Yes(1) No(11)
• the answer wil be zero.As if 1 letter is inserted in an improper envelope,there must be one another letter which is inserted in an improper env. Thus prob that exactly 1 lttr is insertd in an improper env is zero
• 13 years agoHelpfull: Yes(1) No(0)
• req probability is pi*r^2/2pi*R=0.5
• 13 years agoHelpfull: Yes(0) No(9)
• req probability is pi*r^2/2pi*R=0.5
• 13 years agoHelpfull: Yes(0) No(6)
• req probability is pi*r^2/2pi*R=0.5
• 13 years agoHelpfull: Yes(0) No(6)
• for one letter their is one envelop proper and 39 is improper..
  so 1/39
• 13 years agoHelpfull: Yes(0) No(4)
• answer is 0
• 12 years agoHelpfull: Yes(0) No(0)