(i)

P(at least one 6)=1-P(no sixes)

That should be easy enough

(ii)

You can identify the combinations possible that give a total of nine or more

6+3

6+4

6+5

6+6

(4 combinations)

5+4

5+5

5+6

(3 combinations)

4+5

4+6

(2 combis)

3+6

(1 combi)

total 5+4+3+1=15 cominbations, all with a probability of 1/36

Answer: 15/36

(iii)

This is the same principle as part II so you should be able to do it now