If

String x = "Computer";	
String y = "Science";

What will the following return?

(a) System.out.print(x.substring(2,6));

(b) System.out.print(x.indexOf(x.charAt(5)));

State the type of errors, if any in the following statements.

(a)

switch (x < 2)

(b)

int a = 100, b = 0;    
System.out.println (a / b);

What will be the output of the following code?

int num = 10; 
if (num < 20)
    System.out.print(num++);
else
    System.out.print(--num);