is there one by the two words above usually used for " percent " ?
or is it usual to use any of them ?
wenlin software gives 百分比 as percent.
mdbg dictionary on line gives 百分之 :-)
A simpler way: % in 国语 (Taiwanese Mandarin) is pronounced pa1.
You can basically take any number: 10 (shi2) and add % (pa1) on the end and you're done.
The answer is there. 三七開定論, 百分率