C :

#include<stdio.h>
int main()
{
    int x;
    scanf("%d",&x);
  
    if(x==1)
        printf("%.1lf",5.0);
    if(x>=2&&x<=5)
        printf("%.1lf",4.5*x);
    if(x>=6&&x<=10)
        printf("%.1lf",4.0*x);
    if(x>10)
        printf("%.1lf",3.5*x);
        return 0;
}

C++ :

#include<bits/stdc++.h>
using namespace std;
int main(){
    int n;
    double r;
    cin>>n;
    
    if(n == 1){
    	r = 5;
	}else if(n >= 2 && n <= 5){
		r = n * 4.5;
	}else if(n >= 6 && n <= 10){
		r = n * 4;
	}else if(n > 10){
		r = n * 3.5;
	}
	
	cout<<fixed<<setprecision(1)<<r;
}

Java :

import java.util.Scanner;
public class Main
{   
	public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        int x = sc.nextInt();
        double a = x*5.0;
        double b = x*4.5;
        double c = x*4.0;
        double d = x*3.5;
        if(x>10) {
        	System.out.println(d);
        }else if(x>=6) {
        	System.out.println(c);
        }else if(x>=2) {
        	System.out.println(b);
        }else {
        	System.out.println(a);
        }
       
    
    }
}

Python :

n = int(input())
if n == 1:
    p = 5
elif 2 <= n <= 5:
    p = 4.5
elif 6 <= n <= 10:
    p = 4
else:
    p=3.5
print("%.1f" % (n*p))