Math question for science

:  If the bacteria doubles every 20 minutes, then one bacterium becomes 2 in 20 minutes (1 multiplied by 2), those 2 become 4 in the next 20 minutes, and then those 4 become 8 in the next 20 minutes, etc… That means that 8 bacteria resulted in 1 hour. Now calculate the growth of bacteria for 15 hours. Your number of bacteria will be HUGE since the number will double every 20 minutes over 15 hours.

show work or explain how you got the answer to get the answer: