I didn't pass the exam because...
-I did my best to answer but I guess, my best was never enough.
-The test was just soooo difficult.
-I didn't study very well because of distraction.
-I finished all my projects before I started studying but ended up having a small amount of time left to study.
-The time provided to answer the test was too short.
- I'm just not good with this stuff, sorry.