Let `A={1,2,..., n}` and `B={a , b` }. Then number of subjections 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={1,2,3,.....n}' and 'B={a,b,c}' , the number of functions from A to B that are onto is

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

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

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

m points on one straight line are joined to n points on another straight line. The number of points of intersection of the line segments thus formed is (A) ^mC-2.^nC_2 (B) (mn(m-1)(n-1))/4 (C) (^mC_2.^nC_2)/2 (D) ^mC_2+^nC_2

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