Question 471557
The bacteria in a 9-liter container double every 4 minutes.
 After 54 minutes the container is full.
 How long did it take to fill a quarter of the container?
:
You can reason this out.
 If it takes 4 min to double, then it would be half full at 50 min, then 1/4 full in 46 min
:
You can confirm this with numbers
:
Find the number of bacteria when full
2^(54/4) = 11585.24
{{{1/4}}} * 11585.24 = 2896.31
let = no. minutes to be 1/4 full
2^(t/4) = 2896.31
using logs
{{{t/4}}} = {{{log(2896.31)/log(2)}}}
{{{t/4}}} = 11.5
t = 11.5 * 4
t = 46 min to be 1/4 full