#include<bits/stdc++.h>
using namespace std;

namespace MyNamespace {
typedef long long ll;

inline namespace MyIO {
	inline ll rd() {
		char ch = getchar();
		ll s = 0, w = 1;
		while (!isdigit(ch)) {
			if (ch == '-') w = -1;
			ch = getchar();
		}
		while (isdigit(ch)) {
			s = (s << 3) + (s << 1) + (ch ^ 48);
			ch = getchar();
		}
		return (s * w);
	}
	template<typename T>
	void wr(T x) {
		if (x < 0) x = -x, putchar('-');
		if (x >= 10) wr(x / 10);
		putchar(x % 10 + 48);
	}
	void wrsp() {
		// pass
	}
	template<typename T, typename... Args>
	void wrsp(T x, Args... args) {
		wr(x), putchar(' '), wrsp(args...);
	}
	void wrln() {
		putchar('\n');
	}
	template<typename T>
	void wrln(T x) {
		wr(x), putchar('\n');
	}
	template<typename T, typename... Args>
	void wrln(T x, Args... args) {
		wrsp(x), wrln(args...);
	}
} // namespace MyIO

inline namespace Base {
	#define bug(x) << #x << '=' << (x) << ' '
	#define siz(A) ll((A).size())

	template<typename T>
	inline T& Max(T &x, const T &y) {
		return x = max(x, y);
	}
	template<typename T>
	inline T& Min(T &x, const T &y) {
		return x = min(x, y);
	}
} // namespace Base

ll n, m;
constexpr inline ll Cn2(ll x) {
	return x * (x - 1) / 2;
}
void solve_tc() {
	n = rd(), m = rd();
	wrln((n - 1) * Cn2((n + m) / (n - 1)) + Cn2((n + m) % (n - 1)));
}

void NamespaceMain() {
	ll T = rd();
	while (T--) {
		solve_tc();
	}
}
}
int main() {
	MyNamespace::NamespaceMain();
	return 0;
}