C# do-while,for QUEST for newbie : I'm starting to learn and practice my tasks over the Internet, I have reached a task that is not very clear to me, would anyone be kind enough to help me?

quest :
Random numbers from 10 to 60 are generated until the number is divisible by 5. This number should be displayed on the screen. Show trial number and average value

I START WITH :
int a;
            do
            {

                Random rnd = new Random();
                a = rnd.Next(10, 60);
             

            }while

BUT I THINK  its wrong