Hi

The number of events is 6^3 = 216 (some of them giving the same sum).

To get 9 the possibilities are :

6-2-1 : 6 events give this result (621,612,261,216,126,162)

5-2-2 : 3 events give this result

5-3-1 : 6 events give this result

4-4-1 : 3 events give this result

4-3-2 : 6 events give this result

3-3-3 : 1 event give this result

Probability is therefore 25/216 = 11.6 %