Question

A bacterium is kept in a nutrient medium divides every 30 minutes. All bacteria produced by the division also continue to divide themselves at the same rate. Due to these divisions the flask is half filled after 9 hours and 30 minutes. How long will it take to have a flask full of bacteria? Suggest the answer with due logical reasoning.

Answer 1

The flask will be full in 10 hours.
Coz if the flask is already half filled with bacteria in 9.5 hrs, we now require the same no. of bacteria to fill the flask completely.
Let's assume the no. of bacteria when the flask is half filled = X
To make it 2X, we require only one more round of division.
Therefore, just one round of division will double the no. of bacteria.
The doubling time is 30 mins.
So, 9.5 + 30 mins = 10 hrs.