C :

#include<stdio.h>
int main()
{
    int x;
    scanf("%d",&x);
    if(x<=10)
        printf("%.1lf",2.0*x);
    if(x>10)
        printf("%.1lf",1.8*x);
        return 0;
}

C++ :

#include<bits/stdc++.h>
using namespace std;
int main(){
	double q;
	int n;
	cin>>n;
	if(n<=10)q=n*2;
	else q=n*2*0.9;
	cout<<fixed<<setprecision(1)<<q<<endl;
	return 0;
}

Java :

import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		double s;
		if(n <= 10){
			s = 2 * n;
			System.out.println(String.format("%.1f", s));
		}else if(n > 10){
			s = 2 * n * 0.9;
			System.out.println(String.format("%.1f", s));
		}
		sc.close();
	}

}

Python :

n = int(input())
if n > 10:
    m = n * 2 * 0.9
else:
    m = n * 2
print('%.1f' % m)