Question

There are four letters and four envelopes. Probability that all letters not placed in the right envelope ?

Answer 1

1/4

Answer 2

answer is 23/24

Answer 3

@Astrophysics

Answer 4

total number of ways in which all letters are placed in the right envelope =1

total number of ways we can arrange the letters and envelops will be 4!=24

total ways in which all letters not placed in the right envelope =total ways -total ways in which they get placed in correct envelop
total ways in which all letters not placed in the right envelope=4!-1 =23

Probability that all letters not placed in the right envelope=23/24

Answer 5

thank you @imqwerty