The average score of all the students in both classes is 84.
<h3>How to calculate the average?</h3>
The class with 30 students had an average score of 80 on a test. The total score will be:
= 30 × 80
= 2400
A class with 20 students had an average score of 90 on the same test. The total score will be:
= 20 × 90
= 1800
Total scores = 2400 + 1800 = 4200
Number of students = 20 + 30 = 50
The average score will be:
= Total score / Total students
= 4200 / 50
= 84
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Answer:
Where are the answer choices
Answer:
a) 
b) 5464 inhabitants.
Step-by-step explanation:
The formula used for compound interest becomes very helpful in this case.

Knowing this, we can easily calculate the value for any year, counting from the original 5000.
From this formula, we can derive a specific one that will serve for any value of <em>t</em>.
a)

b) Apply the formula:

The town will have 5464 inhabitants.