Question

An irrational number between $\frac{1}{7}\mathrm{and}\frac{2}{7}$is
(a) $\frac{1}{2}\left(\frac{1}{7}+\frac{2}{7}\right)$
(b) $\left(\frac{1}{7}\times \frac{2}{7}\right)$
(c) $\sqrt{\frac{1}{7}\times \frac{2}{7}}$
(d) none of these

Answer 1

(c) $\sqrt{\frac{1}{7}\times \frac{2}{7}}$

An irrational number between a and b is given as $\sqrt{ab}$.