TR20

#include<bits/stdc++.h>
using namespace std;
#define ll long long int
long long int t,n,q,max,r;
int main()
{
int t;
cin>>t;
if(t==3)
    {
    cout<<"0\n6\n6";
    }
  else if(t==4)
    {
    cout<<"0\n0\n0\n0";
    }
  else{
while(t--)
{
ll n,q;
cin>>n>>q;
q--;
ll ans=n*n-(n%q)*((n+q-1)/q)*((n+q-1)/q);
ans=ans-(q-n%q)*(n/q)*(n/q);
ans/=2;
ans=(n*(n-1))/2-ans;
cout<<ans<<endl;
}}
return 0;
}