Generate random number

Applications Programming
1

I saw this formula to generate random number between two specified values in shell script.the following.

$(((RANDOM%(max-min+divisibleBy))/divisibleBy*divisibleBy+min))

Give a example in book.
Generate random number between 6 and 30.like this.

$(((RANDOM%30/3+1)*3))

But I have a question , how to get a divisibleBy number is ok.

2

This example might help you: http://www.jr.pl/abs-guide-4.0/random-between.sh