Let `A={1,2,..., n}` and `B={a , b` }. Then number of subjections from `A` into `B` is`n_P_2`(b) `2^n-2` (c) `2^n-1` (d) nC2

Let A={1,2,..., n} and B={a , b }. Then number of surjections from A into B is nP2 (b) 2^n-2 (c) 2^n-1 (d) nC2

Let A={1,2,..., n} and B={a , b }. Then number of surjections from A into B is nP2 (b) 2^n-2 (c) 2^n-1 (d) nC2

Let A="{"1,2"]"a n d\ B={3,4} . Find the total number of relations from A into B.

The sum of first n odd natural numbers is 2n-1 (b) 2n+1 (c) n^2 (d) n^2-1

The mean of first n odd natural number is (a) (n+1)/2 (b) n/2 (c) n (d) n^2

Find sum of sum_(r=1)^n r . C (2n,r) (a) n*2^(2n-1) (b) 2^(2n-1) (c) 2^(n-1)+1 (d) None of these

The number of terms in the expansion of (x+1/x+1)^n is (A) 2n (B) 2n+1 (C) 2n-1 (D) none of these

The arithmetic mean of 1,2,3,...n is (a) (n+1)/2 (b) (n-1)/2 (c) n/2 (d) n/2+1

The arithmetic mean of 1,2,3,...n is (a) (n+1)/2 (b) (n-1)/2 (c) n/2 (d) n/2+1

Let a={1,2},B={0} then which of the following is correct a.Number of possible relations from AtoB is 2^0=1 b.Number of void relations from AtoB is not possible c.Number of possible relations from AtoB are 4 d.Number of possible relations are equal to 2^(n(A)+n(B))