I have this:
double result = 60 / 23;
In my program, the result is 2, but correct is 2,608695652173913. Where is problem?
Haven't used C# for a while, but you are dividing two integers, which as far as I remember makes the result an integer as well.
You can force your number literals to be doubles by adding the letter "d", likes this:
double result = 60d / 23d;