#include <iostream>
#include <vector>
#include <cmath>
#include <cstring>

using namespace std;

int cnt=0, sz;
double ans, tot=0, a;

class SpeedRadar {
	public:
	double averageSpeed(int minLimit, int maxLimit, vector <int> readings) {
		sz=readings.size();
		for(int i=0; i<sz; i++) {
			if(readings[i]>maxLimit || readings[i]<minLimit) cnt++;
			else tot += readings[i];
		}
		if(sz<cnt*10) return 0.0;
		else {
			a=sz-cnt;
			ans=tot/a;
			return ans;
		}
	}
};