If `n>=2` then the number of surjections that can be defined from {1 2 3......n} onto {1 2} is (1) `n^(2)-n` (2)`n^ 2` (3) `2^(n)` (4) `2^(n)-2`

Number of ways in which three numbers in A.P. can be selected from 1,2,3,..., n is a. ((n-1)/2)^2 if n is even b. n(n-2)/4 if n is even c. (n-1)^2/4 if n is odd 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

The total number of ways of selecting two numbers from the set {1,2, 3, 4, ........3n} so that their sum is divisible by 3 is equal to a. (2n^2-n)/2 b. (3n^2-n)/2 c. 2n^2-n d. 3n^2-n

Mean of the numbers 1,2,3,…,n with respective weights 1^(2) + 1, 2^(2) + 2, 3^(2) + 3,…,n^(2)+n is

By the principle of mathematical induction prove that for all natural number 'n' the following statement are true : (a) 2+4+6+........ +2n =n (n+1) (b) 1+4+7+.......+(3n-2) =1/2 n (3n-1) (C) 1^(3)+2^(3)+3^(3) +..........+n^(3)=1/4 n^(2)(n+1)^(2)

Find the sum of the series: 1. n+2.(n-1)+3.(n-2)++(n-1). 2+n .1.

Find the sum of the series: 1. n+2.(n-1)+3.(n-2)++(n-1). 2+n .1.

Let E={1,2,3,4}a n dF={1,2}dot If N is the number of onto functions from EtoF , then the value of N//2 is

Let E={1,2,3,4}a n dF={1,2}dot If N is the number of onto functions from EtoF , then the value of N//2 is