Answer:
We know that the test has 20 questions in total, and she needs 90% correctly. So, we need to find the 90% of 20:

This means that Alyssa needs to answer at least 18 question correctly to get an A.
A.
Base on this result, we can say that Alyssa got an A.
B.
Alyssa needs to answer 18 question to get an A.
C.
Jessie answer three times more questions correct than incorrect.
C=3(I)
C+I=20
3(I)+I=20
4(I)=20
I=20/4=5
C=3(5)=15
According to this result, Jessie only got 15 questions correct.
Therefore, Alyssa got higher percentage of the questions correct.