What is the sum of the first 50 terms of the series `(1xx3)+(3xx5)+(5xx7)+………….?`

Find the sum to n terms of the series 1//(1xx3)+1//(3xx5)+1//(5xx7)+ cdots .

The sum of the first 20 terms of the series (1)/(5xx6)+(1)/(6xx7)+(1)/(7xx8)+backslash is (a) 0.16(b)1.6c(c)16(d) None of these

Finds the sum of first n terms of the series 3/(1^2xx2^2)+5/(2^2xx3^2)+7/(3^2xx4^2)+...... and hence deduce the sum of infinity.

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

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

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

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

Find the sum to n terms of the series 3xx1^2+5xx2^2+7xx3^2+ ………