The requirements for get and set are not approved, while insert and remove are accepted. Can't see why, they are based on the same loop... public static void get10000(List list) { //write your code here Random rand = new Random(); for (int i=0; i<10000; i++) { int n = rand.nextInt(list.size()); list.get(n); } } public static void set10000(List list) { //write your code here Random rand = new Random(); for (int i=0; i<10000; i++) { int n = rand.nextInt(list.size()); list.set(n, "set"); } }