`a_1,a_2, a_3, ,a_n` are in A.P. and `a_1+a_3+a_5+a_7+a_9=20` then `a_5` is `2` 2. `7` 3. `3` 4. `4` 5. 5

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

a_1 , a_2 , ......a_(10) are in G.P a_7/a_5=25 Find a_(10)/a_8

Let a_1,a_2,a_3…… ,a_n be in G.P such that 3a_1+7a_2 +3a_3-4a_5=0 Then common ratio of G.P can be

If a_1,a_2,a_3,. . . ,a_n. . . are in A.P. such that a_4−a_7+a_10=m , then sum of the first 13 terms of the A.P.is

Let a_1,a_2," ..."a_10 be a G.P. If a_3/a_1=25," then "a_9/a_5 equals

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 "a_1,a_2,a_3,.....,a_n" are in AP, prove that "a_(1)+a_(n)=a_(r)+a_(n-r+1)""

Suppose a_1, a_, are real numbers, with a_1!=0. If a_1, a_2,a_3, are in A.P., then A=[a_1a_2a_3a_4a_5a_6a_5a_6a_7] is singular (w h e r ei=sqrt(-1)) The system of equations a_1x+a_2y+a_3z=0,a_4x+a_5y+a_6z=0,a_7x+a_8y+a_9=0 has infinite number of solutions. B=[a_1i a_2i a_2a_1] is non-singular none of these

Let a_1,a_2,a_3 …. a_n be in A.P. If 1/(a_1a_n)+1/(a_2a_(n-1)) +… + 1/(a_n a_1) = k/(a_1 + a_n) (1/a_1 + 1/a_2 + …. 1/a_n) , then k is equal to :