It's C because you need to find how many points each student earned per grade (freshman & sophomore). Then you multiply it by 30 to find out how many points each student scored in the whole class.
Hope this helps!
Answer:
The answer to the problem is 21.1
-4+6*4 = 20
Step-by-step explanation:
If g is equal to 4 the answer is 20
Answer: 9
s = 7
k = 4
x = 6
7 - 4 + 6
3 + 6
9