ISI 2017

Viewing 1 post (of 1 total)
  • Author
    Posts
  • #70865
    Prakash Kapadia
    Participant

    Let A = {1,2,…,n}. For a permutation P = ( P(1),P(2),…,P(n) ) of all elements of A , let P(1) denote the first element of P. Find the first element of P . Find the number of all such permutations P so that for all i,j ∈ A:

    • if i<j<= P(1), then j appears before i in P; and
    • if P(1)<i<j , then i appears before j in P
Viewing 1 post (of 1 total)
  • You must be logged in to reply to this topic.