If `S_(3n)=2S_n` then find the value of `S_(4n)/S_(2n)`

Let S_(n) be the sum of first n terms of and A.P. If S_(3n)=5S_(n) , then find the value of (S_(5n))/(S_(n)) is.

Let S_(n) be the sum of the first n terms of an arithmetic progression .If S_(3n)=3S_(2n) , then the value of (S_(4n))/(S_(2n)) is :

Let S_(n) denote the sum of first n terms of an A.P.If S_(2n)=3S_(n), then find the ratio S_(3n)/S_(n)

For a sequence, if S_(n)=(n)/(n+1) then find the value of S_(10) .

If S_(n)=cos^(n)theta+sin^(n) tehta then find teh value of 3S_(4)-2S_(6)

In an A.P., if S_(n) = n(4n + 1), then the value of S_(20) is

Let S_(n) denote the sum of the first n tem of an A.P.If S_(2n)=3S_(n) then prove that (S_(3n))/(S_(n))=6

If S_(n), denotes the sum of n terms of an AP, then the value of (S_(2n)-S_(n)) is equal to