Cent is 100. Like how a “C-note” is a $100 bill. Per cent is “out of 100.” 50% tariff is “out of every 100 finance units, 50 will get an additional charge.”

50 per cent(100). Percent is the same word mashed together.

I can get how it looks weird to you if you’re used to writing and reading “percent.” It’s kinda like writing “a dios”(to God) instead of “adios”(goodbye) to someone who speaks Spanish. Adios is borrowed from adieu(goodbye) in French. Adieu is the mashed up version of “a dieu”(to God fr) which is the shortened version of “a dieu vous commant”(I commend you to God), which was a proper farewell back in the old old old old days. While all versions of it are technically correct, it still looks weird to someone who always writes “adios” or “adieu.” In a similar fashion, I guess if someone wrote you “good bye” instead of “goodbye,” you’d probably think they dropped a punctuation or something.