typedef long long ll;
typedef long double ld;

#include <bits/stdc++.h>
using namespace std;
#define int long long

signed main(){
    ll n,m;
    std::cin >> n>>m;
    vector<ld> a(n),b(n),p(n);
    for (int i = 0; i < n; i++) {
        std::cin >> a[i]>>b[i]>>p[i];
    }
    map<pair<ll,ll>,ld> memo;
    function<ld(ll,ll)> dfs = [&](ll i, ll j){
        if(memo.find({i,j})!=memo.end())return memo[{i,j}];
        if(i==n)return (ld)0;
        if(j==0)return memo[{i,j}]=dfs(i+1, j)+1/a[i];
        return memo[{i,j}]=max(dfs(i+1, j)+1/a[i], (1/p[i])*(dfs(i+1, j)+1/b[i])+(1-1/p[i])*dfs(i,j-1));
    };
    std::cout << setprecision(20)<<dfs(0, m) << std::endl;
}