Given the function:

This function represents an exponential growth.
Take the exponential growth function:

In an exponential function, the quantity increases slowly at first, then increases rapidly in the later stages.
The function above models an experiment in a science class where the experiment is started with 100 bacteria, then doubles every hour.
From the function, we have the following:

The variable t represent the number of hours since the experiment began
The b(t) represents the number of cells in the bacteria population
ANSWER:
• Hours since the experiment began
• Cells in the bacteria population