USC Placement test?

So I found out that I’m going to have to take the Math and Chem placement test for USC for my major, Computer Science.
However, the only chemistry experience I have is very basic high school level taken about 4 years ago and I forgot everything. What happens if I totally bomb the test?

It’s best to take over. My daughter bombed the language test but somehow got waved into the next class. She said it was obvious her classmates knew way more than she did in French. She had a bad French teacher who taught her very little.

My son got a very low score on the chem placement test (a 16?). And it had absolutely no impact on him since CS (Games) majors don’t have to take chem. I think it’s the same situation for regular CS majors.