Objects and Collections - General Questions

What is the output of the following program?

public class Main {
    public static void main(String[] args) {
        java.util.List<Integer> l = new java.util.ArrayList<>(java.util.List.of(10, 20, 30));
        l.remove(Integer.valueOf(10));
        l.remove(0);
        System.out.println(l);
    }
}

What is the output of the following program?

import java.util.*;
public class Main {
    public static void main(String[] args) {
        Set<String> s = new HashSet<>();
        s.add("a"); s.add("b"); s.add("a");
        System.out.println(s.size());
    }
}

What is the output of the following program?

public class Main {
    public static void main(String[] args) {
        java.util.Map<String, Integer> m = new java.util.TreeMap<>();
        m.put("b", 2); m.put("a", 1); m.put("b", 5);
        System.out.println(m);
    }
}

What is the output of the following program?

public class Main {
    public static void main(String[] args) {
        java.util.Set<String> s = new java.util.HashSet<>();
        s.add("a"); s.add("a"); s.add("b");
        System.out.println(s.size());
    }
}

What is the output of the following program?

import java.util.*;
public class Main {
    public static void main(String[] args) {
        List<Integer> list = new ArrayList<>(List.of(3, 1, 2));
        Collections.sort(list);
        System.out.println(list);
    }
}