Dice throw probability

Favorable outcomes for sum $\ge 9$:

• Sum 9: (3,6), (4,5), (5,4), (6,3) $\implies 4$ cases
• Sum 10: (4,6), (5,5), (6,4) $\implies 3$ cases
• Sum 11: (5,6), (6,5) $\implies 2$ cases
• Sum 12: (6,6) $\implies 1$ case

Total favorable cases $= 4 + 3 + 2 + 1 = 10$. Total sample space $= 36$. Probability $= \frac{10}{36} = \frac{5}{18}$.