(c)
Probability of selecting a white ball from $X$ bag$= \frac{2}{5}$
Probability of selecting a white ball from $Y$ bag
$= \frac{4}{6} = \frac{2}{3}$
Probability of selecting a white ball from $X$ or $Y$ bags
$= \frac{2}{5} + \frac{2}{3} = \frac{16}{15}$
Probability of selecting the white ball from one of the bags
$= \frac{1}{2}.\frac{16}{15} = \frac{8}{15}$