Answer:
74
Step-by-step explanation:
Average is the sum of all the numbers divided by the number of numbers.
We will take average of Quizzes, Homeworks, and Tests. And multiply that by respective weights and find the weighted average of the 90%.
Quiz Avg:
(84+90+72)/3 = 82
Homework Avg:
(80 + 100 + 90)/3 = 90
Test Avg:
(64+72)/2 = 68
Now, weighted avg = [tex]\frac{90(0.1)+82(0.2)+68(0.6)}{0.9}=73.55[/tex]
Rounding it off, we get "74", the correct answer.