Mathematics - Sequence & Series Question with Solution | TestHub

With $\mathrm{a}+\mathrm{c}=2\mathrm{b}$, triangle inequalities $\mathrm{a}+\mathrm{b}>\mathrm{c}$ and $\mathrm{b}+\mathrm{c}>\mathrm{a}$ imply $3\mathrm{b}>2\mathrm{c}$ and $2\mathrm{c}>\mathrm{b}$. Exchange a and c for the same bounds on b/a.