Question

It takes 30 days to completely fill a laboratory dish with bacteria. if the amount of bacteria doubles every day, how many days does it take to half-fill the dish with the bacteria

Answer 1

it will take 29 days to half fill the dish with the bacteria... because. according to the given condition...that .it takes 30 days to completely fill the laboratory dish
...so...till 29 days it fills the half....and in next 1 day it completely fills...as EACH bacteria will divide

I hope u understand

Answer 2

You could think backwards, that is the preceding day, bacteria count was half of what it is today. This means if on day 30, the jar was full with bacteria, the preceding day , jar was half full . Hence, it will take 29 days for bacteria to fill one half of the dish