Synchronized Thread

import java.io.*;
class display
{
synchronized void show(int n)
{
try
{
Thread.sleep(1000);
}
catch(InterruptedException e)
{
}
System.out.println(n+"the multiplication table");
}
}
class fivetable extends Thread
{
display d;
fivetable(display d)
{
this.d=d;
}
public void run()
{
d.show(5);
for(int i=1;i<=5;i++)
System.out.println(i+"*"+5+"="+(i*5));
}
}
class seventable extends Thread
{
display d;
seventable (display d)
{
this.d=d;
}
public void run()
{
d.show(7);
for(int i=1;i<=7;i++)
System.out.println(i+"*"+7+"="+(i*7));
}
}
class tentable extends Thread
{
display d;
tentable (display d)
{
this.d=d;
}
public void run()
{
d.show(10);
for(int i=1;i<=10;i++)
System.out.println(i+"*"+10+"="+(i*10));
}
}
class thread1
{
public static void main(String args[])
{
display d=new display();
fivetable t1=new fivetable(d);
seventable t2=new seventable(d);
tentable t3=new tentable(d);
t1.start();
t2.start();
t3.start();
}
}