Answer:
50 problems total. We know part of this, because it is possible there is extra credit.
Step-by-step explanation:
Normally if you get 100%, you get all the problems right.
So.
86% of (Total problems) = 43 correct
If you divide 43 by 86%, you can get the total number of problems.
Total problems = 43/0.86 = 50 problems
From your great MysticChaCha. :-)