Find the sum of `:` `3/5+5/45+7/45+.....n` terms

Find the sum of 2.3+3.4+4.5+......to n terms.

Find the sum of the series 3xx5+ 5xx7+ 7xx9+ .. to n terms

Find the sum of (i) 20 terms (ii) n terms of the progression 1,3,5,7,9, ....

Find the sum of the series upto n terms 1.3.5+3.5.7+5.7.9+....

The sum of first 9 terms of an arithmetic sequence is 45 and the sum of first 18 terms is 171. Find the sum of 5^(th) to 14^(th) terms.

Find the sum to n term of the A.P.1,3,5,7.....

The sum of first 9 terms of an arithmetic sequence is 45 and the sum of first 18 terms is 171 a) What is the sum of its 10^(th) to 18^(th) terms? b) What is its 5^(th) term? c) Find its 14^(th) term. d). Find the sum of 5^(th) to 14^(th) terms.

Find the sum of the first n terms of the arithmetic sequence 1/n,3/n,5/n,7/n ,.......

Determine the sum of following series upto n terms. 2.1+3.3+4.5+ …….