A huge part of the land for the Jewish part was the Negev desert. And as I said most of the land in general was state owned. Lots of Jewish immigration was expected, which would quickly change the population disparity as well.
You can read the old documents about how they arrived at the plan on the UN’s website.
This is missing a whole slew of buttons and all should be pressed simultaneously. In this media war all arguments from the profound to the ridiculous are used at all times by all sides.