What is the probability of getting a sum 9 from two throws of a dice?

There are 36 permutations of two dice.1 Of these 4 have a sum of 9, specifically 36, 45, 54, and 63. Therefore, the probability of throwing a sum of 9 on two dice is 4 in 36, or 1 in 9, or about 0.1111.

----------------------------------------------------------------------------------

1It does not matter it you throw one die two times or two dice once. Since these are independent events, the probabilities are the same either way.