import java.io.*;
class HitungNilai
{   
   public static void main(String[] args)
    {   String str;
        int tgs,uts,uas;
        double nilai;
        try
        {   FileReader fr = new FileReader("coba1.txt");
            BufferedReader br = new BufferedReader(fr);
            while((str=br.readLine()) != null)
            {   String arrStr[] = str.split("[ ]");
                for(int i=0;i<arrStr.length;)
                {   tgs = Integer.parseInt(arrStr[i++]);
                    uts = Integer.parseInt(arrStr[i++]);
                    uas = Integer.parseInt(arrStr[i++]);
                    nilai = (20*tgs+30*uts+50*uas)/100.0;
                    System.out.printf("%d  %d  %d  %.2f\n",tgs,uts,uas,nilai);
                }
            }
            br.close();
        } catch(IOException e)
        {   System.err.println("File read error");
        }
    }
}

split

public String[] split(String regex)
    Splits this string around matches of the given regular expression.
    This method works as if by invoking the two-argument split method with the given expression and a limit argument of zero. Trailing empty strings are therefore not included in the resulting array.
    The string "boo:and:foo", for example, yields the following results with these expressions:
        Regex 	Result
        : 	{ "boo", "and", "foo" }
        o 	{ "b", "", ":and:f" }
    Parameters:
        regex - the delimiting regular expression 
    Returns:
        the array of strings computed by splitting this string around matches of the given regular expression 
    Throws:
        PatternSyntaxException - if the regular expression's syntax is invalid
    Since:
        1.4
    See Also:
        Pattern