If `S_(k)` denotes the sum of first k terms of a G.P. Then, `S_(n),S_(2n)-S_(n),S_(3n)-S_(2n)` are in

A sequence is called an A.P. if the difference of a term and the previous term is always same i.e. if a_(n+1)-a_(n) = constant (common difference) for all n in N . For an A.P. whose first term is 'a' and common difference is 'd' has its n^("th") term as t_(n)=a+(n-1)d Sum of n terms of an A.P. whose first is a, last term is I and common difference is d is S_(n)=(n)/(2)(2a+(n-1)d) =(n)/(2)(a+a+(n-1)d)=(n)/(2)(a+l) . S_(r) denotes the sum of first r terms of a G.P., then S_(n),S_(2n)-S_(n),S_(3n)-S_(2n) are in

S_(r) denotes the sum of the first r terms of an AP.Then S_(3d):(S_(2n)-S_(n)) is -

If S_(n) , denotes the sum of first n terms of a A.P. then (S_(3n)-S_(n-1))/(S_(2n)-S_(2n-1)) is always equal to

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

If S_(n) denotes the sum of first n terms of an A.P. and S_(2n)= 3S_(n) , then (S_(3n))/(S_(n))=

If S_(n) denotes the sum of first n terms of an A.P., then (S_(3n)-S_(n-1))/(S_(2n)-S_(n-1)) is equal to

If S_(n) denotes the sum of first n terms of an A.P.prove that S_(12)=3(S_(8)-S_(4))

If S_r denotes the sum of the first r terms of an A.P. Then, S_(3n)\ :(S_(2n)-S_n) is n (b) 3n (c) 3 (d) none of these

If S_r denotes the sum of the first r terms of an A.P. Then, S_(3n)\ :(S_(2n)-S_n) is n (b) 3n (c) 3 (d) none of these