#include <bits/stdc++.h>
//              12345678901234567890
#define MAX     1000000008
#define FAST ios_base::sync_with_stdio(0)
using namespace std;
 
int main(){
	FAST;
    int t;
    cin >> t;
    while(t--){
        int piles , starting , pilenow, diff , total;
        cin >> piles >> starting >> diff;
        total = starting;
        pilenow = starting;
        for (int i = 1; i < piles; ++i)
        {
            pilenow = pilenow + diff;
            total += pilenow;
        }
        cout << total << '\n';
    }
    return 0;
}

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MwoxIDEgMQozIDUgNgoyIDEgMg==

3
1 1 1
3 5 6
2 1 2