In a G.P., `T_(2) + T_(5) = 216 and T_(4) : T_(6) = 1 : 4` and all terms are integers, then its first term is

If for a G.P., t_(3)=36 and t_(6) =972, then : t_(8) =

In an A.P., if T_(1) +T_(5)+ T_(10) +T_(15)+ T_(20) + T_(24) = 225, find the sum of its 24 terms.

If for a G.P. { t_(n)}, t_(7) : t_(4) =27 and S_(5) =242, and t_(3) .

If for a G.P. { t_(n)},t_(2) =-6 and t_(5) =48 find S_(7) .

Let {t_(n)} is an A.P If t_(1) = 20 , t_(p) = q , t_(q) = p , find the value of m such that sum of the first m terms of the A.P is zero .

If t_(2)=2 and t_(7)=22 then the sum of first 35terms of an A.P is

If t_(n)=(3+4n) of an ap , then the sum of the its 15 terms is:

If for a G.P., a=8 and t_(4) =64 then : r=