Choosing the wrong class

So I am close to graduation and this semester I am taking the final classes that I need. I am short on 300 level classes. I am taking 6 classes this semester and one needed to be any 300 level class that fit into my schedule. All in need is 300 level credits. How annoying!

So I decided to take a Marine Sedimentology class with the pass/no credit option thinking it would be an easy class and the time fit into my schedule. This was a horrible class to choose! There were no pre-requisites, but this must be a mistake. The class is all math and it is calculus. I only took the first of the 2 semesters of calculus (I ended up changing majors and no longer needing it). This class that I meant to be just an easy class for 300 level credit is probably the hardest class I have ever taken. There are only 4 people total in the class which seems strange to me to even have the class. I have the first test on Monday so I will be studying alot this weekend.