Answer:
1 in 18
Explanation:
The highest possible number Hillary can get is 12, meaning that the only odd number above 10 which she can get is 11.
There are two possible ways in which Hillary can get 11:
(a) Hillary rolls a 5 on her first cube and a 6 on her second cube
(b) Hillary rolls a 6 on her first cube and a 5 on her second cube
There are 34 other possible outcomes which Hillary can have when rolling her number cubes, for a total of 36 possible outcomes.
Since 2 of these outcomes result in a roll of 11, Hillary has a 2 in 36 chance of rolling an 11, which can be simplified as 1 in 18.