There are 500 bacteria at the beginning and they double every 2 hours. So, if you want to find the number of the bacteria after 2 hours, you must multiply 500 by 2; after 4 hours - multiply 500 by 4; after 6 hours - multiply 500 by 8; etc.
You can write it like this:
[tex]x=500 \times 2^{\frac{t}{2}}[/tex]
where x is the number of the bacteria after t hours
[tex]t=24 \\ \\
x=500 \times 2^\frac{24}{2}=500 \times 2^{12}=500 \times 4096=2048000[/tex]
There will be 2,048,000 bacteria after 24 hours.
