Question

in an a.p of 50 term.the sum of first 10th term is 210 and the sum of last 50th term is 2565.find the a.p

Answer 1

let the first term of A.p be a and d be its common difference
now sum of first 10 terms is= 210
and sum of first n terms = n/2( 2a+ (n-1)d)
so,
10/2(2a+ (10-1)d)=210
and 50/2(2a +(50-1)d) = 2565
now solve these two equation to get a and d