Question

A botanist is working with a sample of algae cells in a petri dish. The change in the population of algae cells can be modeled by this function, where I represents the time in minutes

f(t) = 0.89€

Which statement describes the population of algae cells in the sample?

The population is decaying at a rate of 89% per minute,

The population is decaying at a rate of 11% per minute.

The population is growing at a rate of 89% per minute.

The population is growing at a rate of 11% per minute.

Answer 1

The correct answer is b) The population is decaying at a rate of 11% per minute.

Explanation:

Given the function

f(t) = 0.89€

We can see that every time the variable v grows 1, the population grows only 0.89. So the population is decreasing. And the percentage of decreasing we get it by discounting 1 -0.89= 11%

Answer 2

The population is decaying at a rate of 11% per minute.

Explanation:

We have that € is the inicial sample of algae cells, and f(t) shows the sample after t minutes.

As € is multiplied by a number between 0 and 1, that means the sample will decrease it's size as the time passes.

The inicial sample is €, and after 1 minute the sample will be 0.89€, that is, it will decrease by 0.11€ or 11% of the previous sample.

So the correct option is:

The population is decaying at a rate of 11% per minute.