Question

If a, b, c are in hp then  a^-1, b^-1, c^-1 are in _________

(a) GP

(b) HP

(c) AP

(d) None of the mentioned

I got this question during a job interview.

My doubt is from Harmonic Sequences in section Basic Structures: Sets, Functions, Sequences, Sums and Matrices of Discrete Mathematics

Answer 1

Right choice is (c) AP

To elaborate: If a1, a2……… are in AP then  a1^-1, a2^-1………  are in Harmonic Progression.