Wrong grade on my test.

HI,

I am taking Principles of Public Speaking, and just sent Lesson 2 test for grading. It came back with 18 questions correct out of 20, but my grade was 85, instead of 90.

I already checked and all the answers to see if there is a different score from the 0.5 points, but they are all the same.

Can you please let me know?

Thanks,

Simone