Random Numbers help

I am trying to generate a random number between 1 and 100, so I used the following:

Random r = new Random();

int num = r.nextInt(100);

However, I want to make the numbers a little less random.

I want numbers between 20 and 80 to be generated 90% of the time, and the remaining 10% of the time, the other numbers can be generated. So basically, on average, every 10 numbers generated, 9 of them will be between 20 and 80, and only 1 of them will be above or below these values.

Is this possible to do in a fairly simple and easy to understand way?

[583 byte] By [DamianY2J] at [2007-9-30 22:07:27]