For 19 I'm pretty sure it's 12, interesting math problem I came across a while ago.
Post the answers for the holiday chess puzzler 2018 here!
https://www.chess.com/forum/view/general/who-is-the-oldest-person-ever-to-become-grandmaster its an old thread where one asked about the oldest gm ever.

12 is not including occupied squares. 14 is when occupied squares need be attacked. Read all the page!

Did someone find the original photo in no 7? many look alike but wrong type of watch !
Someone remember a tournament with a pink tablecloth and where name was on a folded cardboard? And what is the white part we see in the background?
2nd is Wesley So. Im pretty sure because I watched it live. 3rd the answer is rook. I dont know 4. But 5th one might be chess.com hat because I checked his stream archive and got the hat he wore in 31st October. After that Im not sure about the answers till 14. 15th one is Levon Aronian. 16th one might be Switzerland because I checked up on google and Switzerland had 7 GMs. Im not entirely sure because that data shows the information in 2006. 17th one, I put it up on the analysis board and it showed +0.31 which is very slightly winning for white. Im not sure about the 18th and 19th one. But The answer for the 20th one is Sam Shankland. So please express the answers you know.
where can you check that?
Any other answers you know? Can you please put the answers in like I did? Your answers would be helpful.
. And Is the 7th one Alexandra Kostenuik?