#include <bits/stdc++.h>
using namespace std;
using ll=long long;
using ld=long double;
int nibutan(int n, vector<ld> A, ld key){
    int ok=n;
    int ng=-1;
    while(ok-ng>1){
        int mid=(ok+ng)/2;
        if(A[mid]>key){
            ok=mid;
        }else{
            ng=mid;
        }
    }
    return ok;
}

class HLD{
    public:
    int size[200009];
    int inv[200009];
    void start(int n){
        for(int i=1;i<=n;i++){
            size[i]=0;
        }
    }
    void getsize(int n, vector<vector<int>> G, int pos, int par){
        if(G[pos].size()==1){
            size[pos]=1;
            return;
        }
        for(int i:G[pos]){
            if(i==par){
                continue;
            }
            getsize(n, G, i, pos);
            size[pos]+=size[i];
        }
        return;
    }
    int parent[200009];
    int heavyparent[200009];
    void Decomposition(int n, vector<vector<int>> G, int pos, int par, int &id){
        if(par==-1){
            parent[id]=-1;
            heavyparent[id]=id;
        }
        inv[pos]=id;
        int maxid=-1;
        for(int r:G[pos]){
            if(r!=par){
                if(maxid==-1){
                    maxid=r;
                }else{
                    if(size[maxid]<size[r]){
                        maxid=r;
                    }
                }
            }
        }
        if(maxid==-1){
            return;
        }
        id++;
        parent[id]=id-1;
        heavyparent[id]=heavyparent[inv[pos]];
        Decomposition(n, G, maxid, pos, id);
        for(int r:G[pos]){
            if(r!=par&&r!=maxid){
                id++;
                parent[id]=inv[pos];
                heavyparent[id]=id;
                Decomposition(n, G, r, pos, id);
            }
        }
        return;
    }
    //closed ranges [a, b]
    vector<pair<int, int>> getrange(int u, int v){
        u=inv[u];
        v=inv[v];
        vector<pair<int, int>> ans;
        int nu=u;
        int nv=v;
        while(heavyparent[nu]!=heavyparent[nv]){
            if(nu<nv){
                swap(nu, nv);
            }
            ans.push_back({heavyparent[nu], nu});
            nu=parent[heavyparent[nu]];
        }
        ans.push_back({nu, nv});
        return ans;
    }
};
using cur=pair<ll, int>;
int main(){
    int T;
    cin >> T;
    cout << fixed << setprecision(15);
    for(int o=0;o<T;o++){
        ll N, M, K;
        cin >> N >> M >> K;
        ll Q=K/M;
        ll R=K%M;
        if(K<=(N-1)*M){
            ld invN=1/(ld)N;
            ld invM=1/(ld)M;
            cout << 1-invN*invM*(Q+min((ll)1,R))<< endl; 
        }else{
            if(K==(N-1)*M+1){
                ld invN=1/(ld)N;
                ld invM=1/(ld)M;
                cout << 1-invM<< endl; 
            }else{
                ld invM=1/(ld)M;
                cout << invM*(M-R) << endl;
            }
        }
    }
}