B S D When the rule depends on whether the majority of guests in a hotel are Jews how can a person decide?

Question:

Paraphrasing this question and answer from another source and not asking you if their answer is correct:
“A non-Jew heats water for coffee and tea in a hotel in which the majority of guests are non-Jews. Can a Jew use the water for his coffee on Shabbat? Yes, he can make his coffee with that water immediately.”
My questions to you are:
1) In general, how can a person know whether the majority of guests in a hotel are non-Jews? (Hotel guests come from elsewhere, check in, go into their rooms and close the doors.)
2) If a person really doesn’t know about the majority does that become equivalent to 50-50 % ?

Answer:

1. You have to figure it out some way to do a simple head count, usually it shouldn’t be that hard, you can either ask at the desk, or maybe see who comes to eat lunch.
2. The halacha says that 50/50 is like a majority of Jews.
3. Best wishes