`a_1,a_2,a_3...,a_n` are in A.P. such that `a_1 + a_3 + a_5 = -12 and a_1a_2a_3=8` then:

If a_1, a_2, a_3 ,........ are in A.P. such that a_1 + a_5 + a_10 + a_15 + a_20 + a_24 = 225 , then a_1 + a_2+ a_3 + ......+ a_23 +a_24 is equal to

Let a_1,a_2,a_3 ......, a_n are in A.P. such that a_n = 100 , a_40-a_39=3/5 then 15^(th) term of A.P. from end is

If for an A.P. a_1,a_2,a_3,........,a_n,........a_1+a_3+a_5=-12 and a_1a_2a_3=8, then the value of a_2+a_4+a_6 equals

Three distinct numbers a_1 , a_2, a_3 are in increasing G.P. a_1^2 + a_2^2 + a_3^2 = 364 and a_1 + a_2 + a_3 = 26 then the value of a_10 if a_n is the n^(th) term of the given G.P. is:

If the nonzero numbers a_1,a_2,a_3,....,a_n are in AP, prove that 1/(a_1a_2a_3)+1/(a_2a_3a_4)+...+1/(a_(n-2)a_(n-1)a_n)=1/(2(a_2-a_1))(1/(a_1a_2)-1/(a_(n-1)a_n)) .

If a_1, a_2, a_3,.....a_n are in H.P. and a_1 a_2+a_2 a_3+a_3 a_4+.......a_(n-1) a_n=ka_1 a_n , then k is equal to

If a_1, a_2, a_3,.....a_n are in H.P. and a_1 a_2+a_2 a_3+a_3 a_4+.......a_(n-1) a_n=ka_1 a_n , then k is equal to