Decrement operator, −−, decreases value of variable by what number?

Decrement operator, −−, decreases value of variable by what number?

2) When a=9, b=12 and c=3 what will be the value of x for the expression x=9-12/3+3*2-1

3) What will be the result of the expression of 8|8.

4) What is the output of the following program ?

class Numbers{
    public static void main(String args[])
  {
       int a=20, b=10;
       if((a < b) && (b++ < 25))
  {       System.out.println("This is any language logic");
     }
       System.out.println(b);
          }
 }

5) When one of the operands is real and the other is integer, the expression is called a ……………………. expression.