In a GP, `a_(8) = 192, r=2` then `a_(12)` = …………

In a GP a_(1) = 20 and a_(4) = 540 then r = …………..

Let ( a_(n) ) be a G.P. such that ( a_(4))/( a_(6)) =( 1)/( 4) and a_(2) + a_(5) = 216 . Then a_(1) =

For an increasing G.P. a_(1), a_(2), a_(3),.....a_(n), " If " a_(6) = 4a_(4), a_(9) - a_(7) = 192 , then the value of sum_(l=1)^(oo) (1)/(a_(i)) is

For an increasing G.P. a_(1), a_(2), a_(3),.....a_(n), " If " a_(6) = 4a_(4), a_(9) - a_(7) = 192 , then the value of sum_(l=1)^(oo) (1)/(a_(i)) is

If , in a G.P. {a_(n)} it is given that a_(1)+a_(2)+a_(3)+a_(4) = 30 and a_(1)^(2)+a_(2)^(2)+a_(3)^(2)+a_(4)^(2) =340, then : (a_(1),r) -=

If a_(1), a_(2),………, a_(50) are in G.P, then (a_(1) - a_(3) + a_(5) - ....... + a_(49))/(a_(2) - a_(4) + a_(6) - ....... + a_(50)) =

Given a_(1),a_(2),......,a_(12) are in G.P. If a_(4)*a_(9)=2019 then value of (a_(2)a_(11)+a_(3)a_(10)+a_(5)a_(8)+a_(6)a_(7))/(a_(4)a_(9)) is equal to

If a_(1), a_(2), …, a_(50) are in GP, then " "(a_(1)-a_(3)+a_(5)-…+a_(49))/(a_(2)-a_(4)+a_(6)-…+a_(50)) is equal to :

If the sequence (a_(n)) is in GP, such that a_(4)//a_(6)=1//4 and a_(2)+a_(5)=216, then a_(1) is equal to