Answer:
12, 13, 14.
Explanation:
Since (y+7) must be greater than 18, we know that 7 must be at least 12 (because the next whole number greater than 18 is 19 and 7+12 is 19).
Because of this, three values can be 12, 13, 14. You can really use any three values as long as they are greater than 11.