Answer:
C. 20480
Step-by-step explanation:
so the equation is (60x3) divided by 15 because there are 3 minutes and 60 seconds in each minute and the bacteria doubles every 15 seconds so when you get your answer (12) that is how many times you will double 5.
THE 5 IDENTICAL SHELVES WOULD have to be 76 because if you take 400 - 20 (because that left over) you get 380/5 you get 76 and to check your work you do 5x76=380+20 you get 400 so 76 is you answer
That would be 5/913. As a percent, that would be 0.5%.
I hope this answer helped you! If you have any further questions or concerns, feel free to ask! :)