Question

2) The fish population in a local stream is decreasing at a rate of 3% per year. The population in 2005 was 48,000. What is the population now?

Answer 1

30396 fish.

Explanation:

We are in 2020, that is, 15 years have passed since 2005, to calculate the population it would be:

The first year there would be 48,000, then each year it decreases by 3%, that is, the first one was like this:

48000 - 48000 * 0.03

That is to say:

48000 * (1 - 0.03)

Now, depending on the year number it would be:

48000 * (1-0.03) ^ n

But how were 15 years n = 15, then:

48000 * (1-0.03) ^ 15 = 30396.057

The fish population would be 30396 fish.