In a G.P if `T_2+T_6=25/2 , T_3T_5=25` then find value of `T_2+T_6+T_8`

If t_r denotes the r^(th) term of an G.P. and t_1 t_5 t_10 t_16 t_21 t_25 = 512 , then the value of its 13^(th) term is :

If t_(r) denotes the nth term of an G.P and t_(1)t_(5)t_(10)t_(16)t_(21)t_(25)=512, then the value of its 13th term is:

In an A.P.if S_(1)=T_(1)+T_(2)+T_(3)+....+T_(n)(nodd)dot S_(2)=T_(2)+T_(4)+T_(6)+.........+T_(n) then find the value of S_(1)/S_(2) in terms of n.

If T_(0),T_(1),T_(2),...,T_(n) represent the terms in the expansion of (x+a)^(n), then find the value of (T_(0)-T_(2)+T_(4)-...)^(2)+(T_(1)-T_(3)+T_(5)-...)^(2)n in N

If for an A.P., d=10 , what is the value of t_(6)-t_(2) ?

In an A.P.if S_(1)=T_(1)+T_(2)+T3+...+T_(n) (n odd S_(2)=T_(1)+T_(3)+T_(5)+...+T_(n) then (S_(1))/(S_(2))=