i am solving the question with c but i am unable to resolve the error of testcase 2 and 3 from my code my code. can any one help me ? my code is as follow:

 int T,i,k;
int N,sum;
scanf("%d",&T);
for(i=0;i<T;i++)
    {
    sum=0;
    scanf("%d",&N);
    for(k=1;k<N;k++)
        {
        if(k%3==0||k%5==0)
        sum=sum+k;
    }
    printf("%d\n",sum);
}