class Fraction_Error(Exception):
    pass

class Fraction():
    ##入力定義
    def __init__(self,Numerator=0,Denominator=1):
        """分数のオブジェクトを生成する.

        Numerator:分子
        Denominator:分母 (!=0)
        """
        assert Denominator,"分母が0"

        if Denominator<0:
            Numerator*=-1
            Denominator*=-1

        self.a=Numerator
        self.b=Denominator
        self.__reduce()

    #表示定義
    def __str__(self):
        if self.b==1:
            return str(self.a)
        else:
            return "{}/{}".format(self.a,self.b)

    def __repr__(self):
        return self.__str__()

    #四則演算定義
    def __add__(self,other):
        if other.__class__==Fraction:
            x=self.a*other.b+self.b*other.a
            y=self.b*other.b
        elif other.__class__==int:
            x=self.a+self.b*other
            y=self.b
        else:
            assert 0,"型が違う"

        C=Fraction(x,y)
        C.__reduce()
        return C

    def __radd__(self,other):
        return self+other

    def __sub__(self,other):
        if other.__class__==Fraction:
            x=self.a*other.b-self.b*other.a
            y=self.b*other.b
        elif other.__class__==int:
            x=self.a+self.b*other
            y=self.b
        else:
            assert 0,"型が違う"

        C=Fraction(x,y)
        C.__reduce()
        return C

    def __rsub__(self,other):
        return -self+other

    def __mul__(self,other):
        if other.__class__==Fraction:
            x=self.a*other.a
            y=self.b*other.b
        elif other.__class__==int:
            x=self.a*other
            y=self.b
        else:
            assert 0,"型が違う"

        C=Fraction(x,y)
        C.__reduce()
        return C

    def __rmul__(self,other):
        return self*other

    def __floordiv__(self,other):
        if other==Fraction():
            raise ZeroDivisionError

        H=self/other
        return H.a//H.b

    def __rfloordiv__(self,other):
        if self==Fraction():
            raise ZeroDivisionError

        H=other/self
        return H.a//H.b

    def __truediv__(self,other):
        assert other,"除数が0"

        if other.__class__==Fraction:
            x=self.a*other.b
            y=self.b*other.a
        elif other.__class__==int:
            x=self.a
            y=self.b*other
        else:
            assert 0,"型が違う"

        C=Fraction(x,y)
        C.__reduce()
        return C

    def __rtruediv__(self,other):
        assert self,"除数が0"
        T=self/other
        return Fraction(T.b,T.a)

    def __pow__(self,m):
        self.__reduce()

        alpha,beta=self.a,self.b
        if m<0:
            alpha,beta=beta,alpha
            m=-m

        return Fraction(pow(alpha,m),pow(beta,m))

    #丸め
    def __floor__(self):
        self.__reduce()
        return self.a//self.b

    def __ceil__(self):
        self.__reduce()
        return (self.a+self.b-1)//self.b

    #真偽値
    def __bool__(self):
        return bool(self.a)

    #比較
    def __eq__(self,other):
        if other.__class__==Fraction:
            return self.a*other.b==self.b*other.a
        elif other.__class__==int:
            return self.a==self.b*other
        else:
            assert 0,"型が違う"

    def __nq__(self,other):
        return not(self==other)

    def __lt__(self,other):
        return self<=other and self!=other

    def __le__(self,other):
        self.__reduce()
        if other.__class__==Fraction:
            other.__reduce()
            return self.a*other.b<=self.b*other.a
        elif other.__class__==int:
            return self.a<=self.b*other
        else:
            assert 0,"型が違う"

    def __gt__(self,other):
        return other<=self and other!=self

    def __ge__(self,other):
        return other<=self

    #その他
    def __float__(self):
        return self.a/self.b

    def sign(self):
        s=self.a*self.b
        if s>0:return 1
        elif s==0:return 0
        else:return -1

    def __reduce(self):
        a,b=self.a,self.b
        x=abs(a)
        y=b

        while y:
            x,y=y,x%y

        self.a//=x
        self.b//=x

    #符号
    def __pos__(self):
        return self

    def __neg__(self):
        return Fraction(-self.a,self.b)

    def __abs__(self):
        if self.a>0:
            return self
        else:
            return -self

    #その他
    def is_unit(self):
        self.__reduce()
        return self.a==1

class Coloring_Union_Find():
    def __init__(self,N,f,e=0):
        """0,1,...,n-1を要素として初期化する.

        N:要素数
        f:2変数関数の合成
        e:最初の値
        """
        self.n=N
        self.parents=[-1]*N
        self.data=[e]*N
        self.rank=[0]*N
        self.f=f

    def find(self, x):
        """要素xの属している族を調べる.

        x:要素
        """
        V=[]
        while self.parents[x]>=0:
            V.append(x)
            x=self.parents[x]

        for v in V:
            self.parents[v]=x
        return x

    def union(self, x, y):
        """要素x,yを同一視する.

        x,y:要素
        """
        x=self.find(x)
        y=self.find(y)

        if x==y:
            return

        self.data[x]=self.data[y]=self.f(self.data[x],self.data[y])

        if self.rank[x]<self.rank[y]:
            x,y=y,x

        self.parents[x]+=self.parents[y]
        self.parents[y]=x

        if self.rank[x]==self.rank[y]:
            self.rank[x]+=1

    def size(self, x):
        """要素xの属している要素の数.

        x:要素
        """
        return -self.parents[self.find(x)]

    def same(self, x, y):
        """要素x,yは同一視されているか?

        x,y:要素
        """
        return self.find(x) == self.find(y)

    def set(self,x,c):
        """要素xの属する成分の色をcに変更する.

        x:要素
        c:色
        """
        self.data[self.find(x)]=c
        return

    def look(self,x):
        """要素xの属する成分の色

        x:要素
        """
        return self.data[self.find(x)]

    def members(self, x):
        """要素xが属している族の要素.
        ※族の要素の個数が欲しいときはsizeを使うこと!!

        x:要素
        """
        root = self.find(x)
        return [i for i in range(self.n) if self.find(i) == root]

    def roots(self):
        """族の名前のリスト
        """
        return [i for i,x in enumerate(self.parents) if x < 0]

    def group_count(self):
        """族の個数
        """
        return len(self.roots())

    def all_group_members(self):
        """全ての族の出力
        """
        X={r:[] for r in self.roots()}
        for k in range(self.n):
            X[self.find(k)].append(k)
        return X

    def color_list(self):
        return [self.look(x) for x in range(self.n)]

    def color_map(self):
        return {x:self.look(x) for x in self.roots()}

    def __str__(self):
        return '\n'.join('{} [color:{}]: {}'.format(r,self.look(r),self.members(r)) for r in self.roots())

    def __repr__(self):
        return self.__str__()

def adder(x,y):
    if x==inf or y==inf:
        return inf
    else:
        return x+y
#================================================
import sys
from decimal import Decimal
input=sys.stdin.readline
write=sys.stdout.write

N=int(input())
A=["*"]+list(map(int,input().split()))
B=["*"]+list(map(int,input().split()))
P=["*"]+list(map(int,input().split()))

inf=float("inf")
U=Coloring_Union_Find(N+1,lambda x,y:[x[0]+y[0],x[1]+y[1]],[0,0])

Ans=Fraction()
for i in range(1,N+1):
    d=A[i]-B[i]
    Ans+=d*d*P[i]
    if P[i]:
        U.set(i,[d,Fraction(1,P[i])])
    else:
        U.set(i,[d,inf])


Q=int(input())
S=[0]*Q
for q in range(Q):
    X,Y=map(int,input().split())

    if not U.same(X,Y):
        d,p=U.look(X)
        Ans-=d*d/p
        d,p=U.look(Y)
        Ans-=d*d/p

        U.union(X,Y)
        d,p=U.look(X)
        Ans+=d*d/p

    S[q]=Decimal(Ans.a)/Decimal(Ans.b)

write("\n".join(map(str,S)))