06. Speed Info

import java.util.Scanner;

public class SpeedInfo {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        double speed = Double.parseDouble(scanner.nextLine());

        if (speed <= 10) {
            System.out.println("slow");
        } else if (speed <= 50) {
            System.out.println("average");
        } else if (speed <= 150) {
            System.out.println("fast");
        } else if (speed <= 1000) {
            System.out.println("ultra fast");
        } else if (speed > 1000) {
            System.out.println("extremely fast");
        }
    }
}

ИЛИ:

import java.util.Scanner;

public class SpeedInfo {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        double speed = Double.parseDouble(scanner.nextLine());

        String info =
                speed <= 10 ? "slow" :
                        speed <= 50 ? "average" :
                                speed <= 150 ? "fast" :
                                        speed <= 1000 ? "ultra fast" : "extremely fast";

        System.out.println(info);
    }
}