Ten IIT and 2 DCE students sit in a row. The number of ways in which exactly 3 IIT student sit between 2 DCE students is `(A)` `.^10 C_3xx2!xx3!xx8!` `(B)` `10 !xx2!xx3!xx8!` `(C)` `5!xx2!xx9!xx8!` `(D)` none of these

Is 7 xx 5 xx 3 xx 2 + 3 a composite number? Justify your answer.

If set A={1, 2, 3, 2 } , then the find the number of onto functions from A to A such that f(k) is a multiple of 3, whenever k is a multiple of 4. (A) 6^5xx15! (B) 5^6xx15! (C) 6!xx5! (D) 6!xx15!

A person predicts the outcome of 20 cricket matches of his home team. Each match can result in either a win, loss, or tie for the home team. Total number of ways in which he can make the predictions so that exactly 10 predictions are correct is equal to a. ^20 C_(10)xx2^(10) b. ^20 C_(10)xx3^(20) c. ^20 C_(10)xx3^(10) d. ^20 C_(10)xx2^(20)

Find the sum to n terms of each of the series in 1xx 2 xx 3 + 2 xx 3 xx 4 + 3 xx 4 xx 5 + ...

The sum of the series 1 + 2 xx 3 + 3 xx 5 + 4 xx 7+ ...upto 11th term is

Find the sum to n terms of the series : 1xx2xx3 + 2xx3xx4 + 3xx4xx5 + dot dot dot

Find the sum to n terms of each of the series in 1xx2+2xx3+3xx4+4xx5+....