Hi Friend,

You have used semi colon (;) with the declaration of mul(int x,int y) therefore you have got those errors.

Your code:

class mathoperation
{
static int add(int p,int q)
{
return(p+q);
}
static int mul(int x,int y)
{
return(x*y);
}
static int div(int c,int d)
{
return(c/d);
}
static int sub(int m, int n)
{
return(m-n);
}
}
class mathdemo
{
public static void main(String args[])
{
int r=mathoperation.add(10,20);
System.out.println("addition="+r);
int s=mathoperation.mul(10,20);
System.out.println("Multiplication="+s);
int t=mathoperation.div(10,20);
System.out.println("division="+t);
int o=mathoperation.sub(10,20);
System.out.println("subtraction="+o);
}
}

Thanks