" (1) "2,4,6,8,cdots

If (1.2+2.3+3.4+cdots "to n terms")/(1+2+3+cdots "to n terms") =6 find n.

If A={2,4,6,8}then

Let A, be the sum of the first n terms of the geometric series 704 + (704)/(2) +(704)/(4) +(704)/(8)+ cdots and B_(n) , be the sum of the first n terms of the geometric series 1984 - (1984)/(2) + (1984)/(4) -(1984)/(8) + cdots If A_(n), =B_(n) , then the value of n is (where n in N).

Prove that "cos" (2pi)/15 cdot "cos"(4pi)/15 cdot "cos" (8pi)/15 "cos"(14pi)/15=1/(16)

If U={1,2,3,4,5,6,7,8} , A = {2,4,6,8} and B={2,4,8} then: Write A’, B’ .

If U ={1,2,3, 4,5,6,7,8} and A={2,4,6,8} , Find (i) A' (ii) (A')' .

Let R be a relationon N defined by x+2y=8. The domain of R is (a) {2,4,8} b. {2,4,6,8} c. {2,4,6} d. (1,2,3,4)

Find the sum of n terms and sum to infinity of the following series : (1)/(2cdot4)+(1)/(4cdot6)+(1)/(6cdot8)+…