1. ## exponential

Please, can someone help me w/this?

A biologist finds that the population of a certain type of bacteria doubles each half-hour. An initial culture has 90 bacteria. How long will it take for the number of bacteria to reach 368,640?

Thank you.

2. Originally Posted by pexler
Please, can someone help me w/this?

A biologist finds that the population of a certain type of bacteria doubles each half-hour. An initial culture has 90 bacteria. How long will it take for the number of bacteria to reach 368,640?

Thank you.
Hi

Let n be the number of half-hours and q(n) the quantity of bacteria

$q(n) = 90 \cdot 2^n$

q(n) = 368,640 for $\frac{368,640}{90} = 4096 = 2^n$ which gives n=12

It will take 6 hours