1. Which of the following classes are available in the java.lang package? (A) Stack (B) Object (C) Math (D) Random (E) String (F) StringBuffer (G) Vector   (C), (E) & (F)   (B), (E) & (F)   (B), (C) & (E)   (B), (C), (E) & (F)   (A), (B), (C), (E) & (F)   Hint Half-n-half Clue   2. Given the following code: class Base { int x = 10; } class Derived extends Base { int x = 20; } Base b = new Base(); Derived d = new Derived ( ); Base bd = new Derived(); The statement System.out.println(b.x + " " + d.x + " " + bd.x); will produce the output   10 20 20   20 20 10   10 20 10   20 10 20   Half-n-half Clue   3. Which of the following methods belong to the String class?   All of these   length()   equals()   None of these   substring()   compareTo()   Half-n-half Clue   4. Which of the following are the wrapper classes? (A) Random (B) Byte (C) Vector (D) Integer (E) Short (F) Double (G) String   (D), (E) & (F)   (A), (B), (D), (E) & (F)   (B), (D) & (E)   (B), (D) & (F)   (B), (D), (E) & (F)   Half-n-half Clue   5. Consider the following code int number[] = new int[5]; After execution of this statement, which of the following are true? (A) number[0] is undefined (B) number[5] is undefined (C) number[4] is null (D) number[2] is 0 (E) number.length() is 5   (B), (D) & (E)   (E)   (C) & (E)   (A) & (E)   Half-n-half Clue   6. Which of the following contain error? (A) int x[] = int[10]; (B) int[] y = new int[5]; (C) float d[] =   (A), (D) & (E)   (A), (E) & (F)   (A), (D) & (F)   (A), (B), (D), (E) & (F)   (D), (E) & (F)   Half-n-half Clue   7. Suppose that s1 and s2 are two strings. Which of the statements or expressions are valid? (A) String s3 = s1 + s2; (B) String s3 = s1 - s2; (C) s1 <= s2 (D) s1.compareTo(s2); (E) int m = s1.length();   (A), (C) & (E)   (A), (B) & (C)   (C), (D) & (E)   (D) & (E)   (A), (D) & (E)   Half-n-half Clue