#include<cstring>
#include<cmath>
#include<string>
#include<iostream>
#include<algorithm>
using namespace std;
const int maxn = 200010;
const int inf = 0x3f3f3f3f;
const int mo = 1e9+7;
int t,n,m,l,r,res;
double ans;
struct food{
	int w;
	int v;
	double value;
}a[15];
bool cmp(const food a,const food b){
	if(a.value ==b.value )return a.w >=b.w;
	else return a.value >b.value ; 
}
int main(){
	cin>>t;
	for(int k=0;k<t;k++){
		cin>>n>>m;
		for(int i=0;i<n;i++){
			cin>>a[i].w ;
		}
		for(int i=0;i<n;i++){
			cin>>a[i].v ;
			a[i].value =a[i].v *1.0/a[i].w ;
		}
		sort(a,a+n,cmp);
		res=m;
		ans=0;
		for(int i=0;i<n;i++){
			if(res>a[i].w ){
				ans+=a[i].v ;
				res-=a[i].w ;
			}
			else{
				ans+=a[i].value *res;
				break;
			}
		} 
		printf("%.2f\n",ans+1e-7);
	}
	return 0;
}