#include<bits/stdc++.h> 
using namespace std;
int n,tc,TM,a[111],b[111],c[111];
bool check(int misu)
{
	for(int i=1;i<=n;i++)
	{
		int p=(a[i]-b[i])*tc;
		int w=c[i]-b[i]*(TM+tc-misu);
		if(p<w)return false;
	}
	return true;
}
int main()
{
	int g;
	cin>>g;
	while(g--)
	{
		cin>>n>>tc>>TM;
		for(int i=1;i<=n;i++)cin>>a[i]>>b[i]>>c[i];
		int l=0,r=tc+TM+10,mid;
		while(l<=r)
		{
			mid=(l+r)/2;
			if(check(mid))r=mid-1;
			else l=mid+1;
		}
		cout<<mid<<endl;
	}
	return 0;
}