There is an equal probability of 1/10 (0.1 or 10%) of rolling any particular number, that is, if the number is guessed before rolling.
The probability of rolling 2 followed a 9 is 1/10 × 1/10=1/100, for example. But the probability of rolling a 2 and a 9 (that is, 2-9 or 9-2) is 2/100=1/50, provided the prediction is made in advance of rolling.
The probability of rolling the same number twice is 10/100=1/10 because there are ten outcomes out of 100 possibilities: 1-1, 2-2, 3-3, 4-4, 5-5, 6-6, 7-7, 8-8, 9-9, 10-10. The probability of rolling two different numbers is 90/100=9/10.
These are examples of combining probabilities.
(All cubes have 6 faces, so you can't have a 10-sided cube. It would be a decahedron.)