Which class do I have a better chance of getting into?

<p>I’m currently on the waitlist for Public Health 116 (medical ethics seminar), I’m number 123 in a 400 lecture class. But I also want to take Econ but due to the 16 unit limit I need to drop this class to get on the waitlist for econ. Which would make me 95+ on the waitlist in a 600 lecture.
How much of a chance do I actually have to get into one of these classes?</p>