There are six letters `L_(1),L_(2),L_(3),L_(4),L_(5),L_(6)` and their corresponding six envelops `E_(1),E_(2),E_(3),E_(4),E_(5),E_(6)`. Letters having odd value can be put into odd valued envelopes and even valued letters can be put into even valued envelopes, so that no letter goes into the right envelopes, then number of arrangements equals.

Find the number of ways in which 4 letters can be put in 4 addressed envelopes so that no letter goes into the envelope meant for it.

In how many ways we can put 5 letters into 5 corresponding envelopes so that atleast one letter go the wrong envelope?

3 Letters are placed in 3 envelopes randomly. The probability that only one letter goes in right envelope is A 1/2 B 1/3 C 1/6 D 2/3

A person writes letters to 6 friends and addresses a corresponding envelope. The number of ways in which 5 letters can be placed in the wrong envelope is?

A: There are 4 letters and 4 addressed envelopes. If the letters are put in the random in the envelopes , the probability that all the letters may be placed in wrongly addressed envelopes is 3//8 . R: If n letters are put at random in the n addressed envelopes , the probability that all the letters may be in wrong envelopes = 1- (1)/(1!) +(1)/(2!)-(1)/(3!)+.....+((-1)^(n))/(n!)