There are 4 addressed envelopes the letters are placed at random at random the prob that not all 4 letters are placed in correct envelope

ans me in detail plzzz

• Let 4 envelopes be ABCD nd 4 letters be abcd....
  
  P(none are placed in correct envelope) = 1-P(all are placed in correct env)
  
  P(letters arranged in 4 env) = 4! = 24
  
  No. of ways of placing all letters in correct env. is
  abcd in ABCD => only one way => 1
  
  P(All are placed in correct env.) = 1/24
  
  P(none are placed in correct env) = 1-1/24 = 23/24
  
  Ans : 23/24
• 10 years agoHelpfull: Yes(14) No(0)
• i think 23/24
• 10 years agoHelpfull: Yes(2) No(1)
• 256-1=255
  total ways=256
  only one way that all letters in right envelopes
  so required nos=256-1=255
• 10 years agoHelpfull: Yes(1) No(0)
• Details plzz..
  
• 10 years agoHelpfull: Yes(0) No(0)
• the no of ways to place all the addresses on the correct envelope = 1
  total no of ways = 4^4 = 256
  now,
  the prob of placing correct envelope = 1/256
  thus, prob for not correct envelope = 1- 1/256=255/256 ans...
• 10 years agoHelpfull: Yes(0) No(0)