A bacteria culture doubles in size every 20 min. How long will it take for a culture of 50 bacteria to grow to a population of 250 000?Exponential Equations

1 Answer

embizze's profile pic

embizze | High School Teacher | (Level 2) Educator Emeritus

Posted on

Given the initialpopulation is 50 and the growth rate is 2: find how long until the population is 250,000.

The formula is `A=P*b^t` where A is the population at time t, P the initial population and b the growth rate.

If t is in hours:


`==> 2^(3t)=5000`






It will take approximately 4hrs 6 min for the population to reach 250000.


If you prefer to work in minutes:

`250000=50*2^(t/20)` where t is in minutes. Then:


`t=(ln5000)/(ln2)*20~~245.754` minutes which is about 4.1 hours as above.