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

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

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

If a_(1) , a_(2), a_(3) , cdots ,a_(n) are in A.P. with a_(1) =3, a_(n) =39 and a_(1) +a_(2) + cdots +a_(n) =210 then the value of n is equal to

If a_(n) is a geometric sequence with a_(1)=2 and a_(5)=18, then the value of a_(1)+a_(3)+a_(5)+a_(7) is equal to

If a_(n+1)=a_(n-1)+2a_(n) for n=2,3,4, . . . and a_(1)=1 and a_(2)=1 , then a_(5) =

Consider an A.P*a_(1),a_(2),a_(3),.... such that a_(3)+a_(5)+a_(8)=11 and a_(4)+a_(2)=-2 then the value of a_(1)+a_(6)+a_(7) is....

If the sequence a_(1),a_(2),a_(3) ,…….. Is an A.P., then the sequence a_(5), a_(10), a_(15) ,…….. Is ………..

If a_(1) , a_(2), "……………" a_(n) are in H.P., then the expression a_(1) a_(2) + a_(2) a_(3)+"…….."+ a_(n-1) a_(n) is equal to :

If a_(1), a_(2) , ……. A_(n) are in H.P., then the expression a_(1)a_(2) + a_(2)a_(3) + ….. + a_(n - 1)a_(n) is equal to

A geometric sequence has four positive terms a_(1),a_(2),a_(3),a_(4). If (a_(3))/(a_(1))=9 and a_(1)+a_(2)=(4)/(3) then a_(4) equals