Dynamically changing number of nested loops

Question

I am learning Java - ran into this problem:

Write a program in which a roll of n cubes, where the bones are all d-sided. From using a simulation, report an approximate probability value that rolls all x or more, using dice, where x, n and d are all data as input. For example, if n = 2, d = 6, and x = 7, the program should report a probability of 58.3% (approximately).

Here is what I came up with

public class Main {

    public double calcProbability(int n, int d, int x){
        int[] sums = new int[(int)Math.pow(d, n)]; //Creates an array of max size needed
        int counter = 0;    
        int occurrences = 0; //No. of times that the number being added to the array is greater than d
        for(int i=1;i<=d;i++){
            for(int j=1;j<=d;j++){
                if((i+j)>=x){
                    occurrences++;
                }
                sums[counter]=(i+j);
                counter++;
            }
        }
        return (double)occurrences/Math.pow(d, n); //Returning probability
    }

    public static void main(String[] args) {
        System.out.println(new Main().calcProbability(2, 6, 7));
    }

}

It works fine for n = 2 (I think), since I use two nested loops. But it’s hard for me to understand how to change the number of loops with n (this will allow me to add all the possible totals to the array - the rest of the code should work fine, as it is).

Would thank for some recommendations.

---

Thanks to everyone, after considering each contribution, here is the revised method:

public double calcProbability(int n, int d, int x){
        Random random = new Random(); //Random numbers simulate dice rolling
        int occurrences = 0; //No. of times that the number is greater than d
        for(int i=0;i<100000;i++)
        {
            int sum = 0;
            for(int j=0;j<n;j++)
            {
                sum+=random.nextInt(d)+1;
            }
            if(sum>=x) {
                occurrences++;
            }

        }
            return (double)occurrences/100000; //Will be an approximation
    }

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Answer 1

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public double calcProbability(int n, int d, int x){
        Random random = new Random(); //Random numbers simulate dice rolling
        int occurrences = 0; //No. of times that the number is greater than d
        for(int i=0;i<100000;i++)
        {
            int sum = 0;
            for(int j=0;j<n;j++)
            {
                sum+=random.nextInt(d)+1;
            }
            if(sum>=x) {
                occurrences++;
            }

        }
            return (double)occurrences/100000; //Will be an approximation
    }

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Answer 2

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Answer 3

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n all [1, d].

:

int occurrences = 0;
int count = 0;
Result result = new Result(n, 1); // n times 1.
while(result != null)
{
    if (result.Sum >= x) occurrences++;
    count++;

    GetNextResult(result);
}

double probability = occurrences / (double) count;

GetNextResult null, [d, d, ..., d].

, Result.