Problem on Sum of the first n terms of AP

If the sum of the first 2n terms of the A.P.2,5,8,…, is equal to the sum of the first n terms of the A.P.57,59,61,…, then n equals

The sum of the first five terms of an AP and the sum of the first seven terms of theits first twenty terms.same AP is 167. If the sum of the first ten terms of this AP is 235, find the sum of first twenty terms

The sum of the first n terms of an AP is given by S_(n) =n^(2)+5n .find the sixteenth term of the AP.

If sum of first 20 terms of an A.P. is equal to sum of first 30 terms of the A.P. then sum of the first 50 terms of the A.P. is

(i) The sum of the first n terms of an AP is ((5n^(2))/(2) + (3n)/(2)) . Find the nth term and the 20th term of this AP. (ii) The sum of the first n terms of an AP is ((3n^(2))/(2) + (5n)/(2)). Find its nth term and the 25th term.

If the sum of the first n terms of an AP is 4n-n^(2) ,what is the first term (that is )? What is the sum of first two terms? What is the second term? Similarly,find the 3rd, the 10th and the nth terms.

If the sum of the first n terms of an AP is given by S_n=3n^2-n then find its nth terms, first term and common difference