Question 927913
1st Question:
Can you earn an A?
Yes. You need to have 98% in your last test in order to get an 90% final grade in your semester.

To get a final grade of 90% in your semester:
(85+80+94+93+x)/5 = 90

Multiply each side by 5
85+80+94+93+x=450
        352+x=450
            x= 98

2nd Question:
Can you earn an A?
No. You need at least 105% in order to have 90% final grade in your semester. Since the maximum possible score is 100%, the highest grade you can get is 89%.

To get a final grade of 90% grade in your semester:

(82+84+83+96+x)/5 = 90

Multiply each side by 5
82+84+83+96+x=450
        345+x=450
            x=105

Highest attainable grade:
(82+84+83+96+100)/5 = 89