10 books can be rearranged in 10! ways consider the two books taken as a pair then number of favourable ways of getting these two books together is 9! 2!
Required probability = 1/5
10 books are placed at random in a shelf. The probability that a pair of books will always be together i
Options:
  - 1/6
  - 1/0
  - 1/5
  - 1/2
  - 1/1