If `a_1,a_2,a_3` …. are in harmonic progression with `a_1=5` and `a_20=25`. Then , the least positive integer n for which `a_n lt 0` , is :

Let a_1 , a_2 ,... be in harmonic progression with a_1 = 5 and a_20 = 25 . The least positive integer n for which a_n lt 0

Let, a_1,a_2,a_3,…. be in harmonic progression with a_1=5 " and " a_(20)=25 The least positive integer n for which a_n lt 0

Let a_1,a_2,a_3,... be in harmonic progression with a_1=5a n da_(20)=25. The least positive integer n for which a_n<0

Let, a_1,a_2_a,a_3,…. be in harmonic progression with a_1=5 " and " a_(20)=25 The least positive integer n for which a_n lt 0

Let a_1,a_2,a_3,... be in harmonic progression with a_1=5a n da_(20)=25. The least positive integer n for which a_n<0 a. 22 b. 23 c. 24 d. 25

If a_1,a_2,a_3,…….a_n are in Arithmetic Progression, whose common difference is an integer such that a_1=1,a_n=300 and n in[15,50] then (S_(n-4),a_(n-4)) is

If a_1,a_2,a_3,…….a_n are in Arithmetic Progression, whose common difference is an integer such that a_1=1,a_n=300 and n in[15,50] then (S_(n-4),a_(n-4)) 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)""

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:

A sequence of positive integers a_1 , a_2, a_3, …..a_n is given by the rule a_(n + 1) = 2a_(n) + 1 . The only even number in the sequence is 38. What is the value of a_2 ?