Solution in C
Code
# Code
```c []
int countPairs(int* nums, int numsSize, int k) {
    int count=0;
    for(int i=0;i<numsSize-1;i++){
        for(int j=i+1;j<numsSize;j++){
            if(nums[i]==nums[j] && (i*j)%k==0) count++;
        }
    }
    return count;
}
```
['C']