Let $E_1$ be the event that the sum of faces $= 9$
This can happen with the following cases:
$(3, 6), (4, 5), (5, 4) \ \ \& \ \ (6, 3)$
$P(E_1) = \frac{4}{36} = \frac{1}{9}$
Let $E_2$ be the event that the sum is $6$.
$\therefore$ Possibilities are $(1, 5), (2, 4), (3, 3), (4, 2) (5, 1)$
$\therefore P(E_2) = \frac{5}{36}$