math..word problem
posted by M.A. on .
A number of bacteria are placed in a glass. One second later each bacterium divides in two, the next second each of the resulting bacteria divides in two again, etc. After exactly one minute, the glass is full. When was the glass half full?

obviously at the 59 second mark.
At this point the glass is halffull
They all double to make the glass full in the next second 
Assume his small imagine has 1 parental cell; Salmonella reproduces every 30 minutes. How many bacteria after 12 hours