Let A={1,2,…,n}. For a permutation P=(P(1),P(2),…,P(n)) of the elements of A, let P(1) denote the first element of P. Find the number of all such permutations P so that for all i,j∈A:(a) if i<j<P(1), then j appears before i in P; and(b) if P(1)<i<j, then i appears before j in P. number theorycountingcombinatoricscontests