Question

The set of gold medalists in the 2014 Winter Olympic games in set builder notation.

I don't get what I'm supposed to do.

Answer 1

Am I supposed to know how many gold medalists were in the 2014 winter Olympic games?
Like when they ask for set builder notation for vowels, I get it is {a,e,i,o,u}
A = {x l x is a vowel}

Answer 2

Or I just write it like A= {x l x is the number of gold medalists in the 2014 Winter Olympic games).

Answer 3

My second and last question:
For { x l x is a digit in the number 351,646}, the roster would be written as {2,3,4,5,6} right?

Answer 4

your answers are good, except for the gold medalists.
That would just be a list of names of the winners.
If such a list is hard to determine, or too long to be easily listed, or if the actual names are unimportant, then I'd just go with

A= {x l x was a gold medalist in the 2014 Winter Olympic games}