Question

The country of Sylvania has decided to reduce the number of its illiterate citizens by 3/5 each year. This year there are 9000 illiterate people in the country.

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Write a function that gives the number of illiterate people in Sylvania, P(t), t years from today

Answer 1

P(t)= 9000(0.4)^t

Explanation:

Generally, we have an exponential function as follows;

P(t)= I(1 - r)^t

This case represents a decay ( decrease in value)

from what we have;

I represents the initial value, whereas r is the rate of change

From the question, we have that the change rate is the fraction 3/5

Writing this as a decimal, it is 0.6

substituting this back into the equation, we have;

P(t)= I(1-0.6)^t

P(t)= I(0.4)^t

I in this case is 9,000

So we have it that;

P(t) = 9000(0.4)^t