C :

#include <stdio.h>
#include <stdlib.h>

int main()
{

    float a,b;
    scanf("%f",&a);
    if(a<=3)
        printf("8.00yuan");
    if(a>3)
    {
        b=8+(a-3)*1.6;
        printf("%.2fyuan",b);
    }

}

C++ :

#include<iostream>
#include<cstdio>
using namespace std;
int main()
{
	double dist,fee;
	cin>>dist;
	if (dist<3.0) fee=8;
	else fee=1.6*(dist-3)+8;
	printf("%.2lfyuan\n",fee);
	return 0;
}

Pascal :

var
  n:extended;
  s:extended;
begin
  readln(n);
  n:=n-3;
  s:=8+1.6*n;
  writeln(s:0:2,'yuan');
end.