#include <bits/stdc++.h>
using namespace std;
#define     mod     1000000007
#define     int      long long 
#define     pb      push_back
#define     endl    '\n'
#define     ff      first
#define     ss      second
#define     FIO     ios_base::sync_with_stdio(0);cin.tie(NULL);cout.tie(NULL);
#define     all(x)  (x).begin(),(x).end()
int32_t main()
{
      FIO
      int t; cin >> t;
      while(t--)
      {
            int n, x, t; cin >> n >> x >> t;
            if(x > t) cout << 0 << endl;
            else 
            {
                  int a = t/x;
                  int ans=0;
                  if(a>n)
                        ans+= (n*(n-1))/2;
                  else
                  {
                        ans+= (n-a) * a;
                        ans+= (a*(a-1))/2;
                  }
                  cout << ans << endl;
            }
      }
}