Suppose 10% of men and 0.5% of women have grey hair. A grey haired person is selected at random. If there are equal number of males and females, then the probability of the selected person being a female is

$\frac{20}{21}$ $\frac{1}{21}$ $\frac{1}{200}$ $\frac{1}{5}$

$\frac{1}{21}$

The correct answer is Option (2) → $\frac{1}{21}$