Rolling the dice! - A question of probability

Here is the scenario. There are 25 individuals. These individuals are rolling a 100 sided die to win a prize. If 10 of these individuals are allowed to add +10 to their roll...

1. What is the percent chance that one of the 10 individuals allowed to add +10 to their roll will win the prize?

2. What is the percent chance that the other 15 individuals rolling 1-100 will have to win the prize?

3. If there are 12 prizes, what is the percent chance of one of the 10 individuals allowed to add +10 winning a prize?

4. If there are 12 prizes, what is the percent chance of one of the 15 individuals rolling 1-100 winning a prize?

5. At the end of 12 rolls what is the projected distribution of these prizes between the two groups?

6. Extra question. What number would you have to add to the 10 individuals roll to have the distribution be 2 prizes for the 10 people every one prize for the 15 people?

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Thank you so much if you are able to help out. If you can show any work that would be amazing.