#include <bits/stdc++.h>
using namespace std;
const int N = 1200;
int n;
const double eps = 1e-9;
double c, t;
double dp[110][110][1110];
double skill[110];
pair<int, int> a[N];
inline bool cmp(pair<int, int> a, pair<int, int> b) {
  return a.first > b.first;
}
inline long long get() {
  int ss = 0;
  for (int i = 1; i <= n; ++i) ss += a[i].second;
  for (int i = 0; i <= n; ++i)
    for (int j = 0; j <= n; ++j)
      for (int b = 0; b <= ss; ++b) dp[i][j][b] = 1e9;
  double s = 1;
  skill[0] = s;
  dp[0][0][0] = 0;
  for (int k = 1; k <= n; ++k) skill[k] = skill[k - 1] * 0.9;
  for (int i = 1; i <= n; ++i) {
    for (int k = 0; k <= n; ++k)
      for (int b = 0; b <= ss; ++b) {
        dp[i][k][b] = min(dp[i][k][b], dp[i - 1][k][b]);
        if (k > 0 && b >= a[i].second) {
          double was = dp[i - 1][k - 1][b - a[i].second];
          was += a[i].first / skill[k];
          dp[i][k][b] = min(dp[i][k][b], was);
        }
      }
  }
  int ans = 0;
  for (int i = 0; i <= n; ++i) {
    if (i * 10 > t) continue;
    for (int b = 0; b <= ss; ++b) {
      double timer = dp[n][i][b];
      if (timer + 10 * i - eps <= t)
        ans = max(ans, b);
      else {
        double l = 1, r = t * c + 1;
        for (int it = 1; it <= 100; ++it) {
          double m1 = l + (r - l) / 3.0;
          double m2 = r - (r - l) / 3.0;
          if (timer / m1 + (m1 - 1) / c <= timer / m2 + (m2 - 1) / c)
            r = m2;
          else
            l = m1;
        }
        double ti = timer / l + (l - 1) / c;
        if (ti - eps + i * 10 <= t) ans = max(ans, b);
      }
    }
  }
  return ans;
}
inline void solve() {
  cin >> n >> c >> t;
  for (int i = 1; i <= n; ++i) cin >> a[i].first >> a[i].second;
  sort(a + 1, a + n + 1, cmp);
  cout << get() << '\n';
}
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  int tc;
  cin >> tc;
  while (tc--) {
    solve();
  }
  return 0;
}
