Mathematics

Problem

Let

p

q

, and

r

be positive numbers such that

\log_{e} p

\log_{e} q

\log_{e} r

are in arithmetic progression. Which one of the following relations among

p

q

, and

r

must hold? a)

p^{2}=qr

p+r=2q

q^{2}=pr

q^{2}=\dfrac{p}{r}