Biology question.....Forgot how I did this how does this answer get to 800?

Question

A test tube is inoculated with 100 cells of a bacterial strain that has a generation time of 30 minutes. The carrying capacity of the test tube for this strain is 6 billion cells. What will the bacterial population be after 90 minutes of culturing?

Correct!

  ~800

 

Answer 1

Generation time is the time it takes for bacteria to double in number. If there are 100 cells in the tube in 30 minutes there will be twice as many-200. In 60 minutes those 200 cells will also double to 400 cells. In 90 minutes those 400 cells will once again double to 800 cells.