Abacteria culture begins with 15 bacteria which double in amount at the end of every hour. solve for the number of bacteria that are grown during the 12th hour.

The number of bacteria is given by:
N(t) = N(o) x 2ⁿ
Where N(t) is the number after n hours have passed and N(o) is the original number which is 15.
The number grown in the 12th hour is the difference in the number after the 11th and the 12th hour. Thus:
15 x 2¹² - 15 x 2¹¹
= 30,720 bacteria

Because it was a dramatically big guy

The answer you are looking for is option d