A bacteria culture begins with 4 bacteria which double in size every hour. How many bacteria exist in the culture after 8 hours?

Question

jamesj · Answer

How many exist is 1 hour?

jamesj · Answer

Write n(0) = the number at the beginning.  We have
n(0) = 4

What's n(1) = # at hour 1?

jamesj · Answer

n(1) = 2 x 4 = 8
because the number of bacteria doubles every hour.

Now, what is
n(2) ?

I'm asking you this so you can get to a formula for n(8).

jamesj · Answer

@kirihara, talk to me.

anonymous · Answer

initial no. of bacterias=4
common ratio(divison)=2
bacterias after 8hrs= ar^n=4x2^8..............rest is calculations..

anonymous · Answer

hey if they doubles its size then after 8 hrs we will be left with those 4 large becterias only!!............there is difference between doubling in size and divison

anonymous · Answer

Never mind found out! XD the answer is 1024 you do (4)(2)^8 the two comes from doubling each hr