How many bacteria?

[Miss_Me]

I was wondering, if a bacteria organism divides once every 20 minutes, how long would it take to produce 2,000,000 (or 2 x 10^6) bacteria cells?

I'm confused on how i'd work this out because i'm getting a sense of there's too many numbers to handle, as each cell divides in 2 every 20 minutes.


please help!

thanks!

[Darby]

The easiest way to work this out is with a table, putting the time intervals next to the total number of cells. You won't need that big a table, either...

0 minutes - 1 cell
20 min - 2
40 - 4.......

[Belana]

x(final) = x(start)*2^n

n = t (time needed) / T (generation period)

2000000 = 1*2^n
log 2000000 = n . log 2
n = 20,93

((20 min = 1/3 h))

20,93 = t / (1/3)
20,93 = 3t

t = 6,97h = cca 6h 58 min