The following document is the 2nd in a series of 3 that looks at previous Math 30-2 released items where the student success rate is under 50%. The 2013 and 2019 set of questions were discussed in other posts. Here you will find the released items from 2016.
Analyzing these most difficult questions can provide valuable insights to both teachers and students.
2013 Version
https://mathpqjq.com/math-30-2-diploma-questions-below-50-2013/
2019 Version
https://mathpqjq.com/math-30-2-diploma-questions-below-50-2019/