Correct Answer - `1 - (1)/(n!)`
Required probability is 1 - P(all letters in right envelope) = 1 - 1/n!
(As there are total number of n! ways in which letters...
Correct Answer - `(11!)/(.^(9)P_(4)xx6! xx 2!)`
Total number of ways of arranging 11 letters is (11)! The number of selection of 4 letters to be placed between R and E from...
Correct Answer - A
`(a)` The other five letters (other than `G`, `R`, `L`, `A`, `S`, `N`) in `11` places can be arranged in `"^(11)P_(5)` ways.
Then three remains six places....
Correct Answer - C
`(c )` The total number of arrangments is `(11!)/(2!2!2!)=(11!)/(8)`
The number of arrangements in which `CE,H,I,S` appear in that order `"^(11)C_(5)(6!)/(2!2!2!)=(11!)/(8*5!)`
`:.` Required Proability `=((11!)/(8*5!))/((11!)/(8))=(1)/(120)`