If `S_(n)` denotes the sum of first n terms of an A.P. and `(S_(3n)-S_(n-1))/(S_(2n)-S_(2n+1))`=31 , then the value n is

If S_n denotes the sum of first n terms of an A.P. and (S_(3n)-S_(n-1))/(S_(2n)-S_(2n-1))=31 , then the value of n is 21 b. 15 c.16 d. 19

Let s_(n) denote the sum of first n terms of an A.P. and S_(2n) = 3S_(n) . If S_(3n) = kS_(n) then the value of k is equal to

If S_(n) denotes the sum of n terms of an A.P., S_(n +3) - 3S_(n + 2) + 3S_(n + 1) - S_(n) =

Let S_(n) denote the sum of first n terms of an A.P. If S_(4) = -34 , S_(3) = - 60 and S_(6) =- 93 , then the common difference and the first term of the A.P. are respectively.

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_ndot

Let S_(n) denote the sum of the first n terms of an AP. If S_(4) = 16 and S_(6) = -48 , then S_(10) is equal to

If S_n denotes the sum of n terms of A.P., then S_(n+3)-3S_(n+2)+3S_(n+1)-S_n= a).2^S_n b). s_(n+1) c). 3S_n d). 0

If S_(n) denotes the sum of n terms of an AP whose common difference is d, the value of S_(n)-2S_(n-1)+S_(n-2) is