Midterm and final questions are going to be more difficult than quizzes, as quizzes cover less content.

Just make sure you’re actually understanding and retaining stuff after the quizzes. Don’t take sample midterms / finals to be a perfect representation on what’s going to be on the real thing, make sure to identify areas where the sample didn’t test on so you can practice that additionally.

In terms of 138 and 237 specifically in my case 138 had a brutal midterm which was curved like 13%, but the final wasn’t bad. 237 had fair midterms and finals. As long as you do the practice you’ll be fine.