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

Question

anonymous · Answer

64 bacteria

anonymous · Answer

@Isaiah.Feynman what do you think

anonymous · Answer

no wait is 32

isaiah.feynman · Answer

There is a basic formula for exponenetial growth I found on wikipedia.

raden · Answer

1st h = 4 * 2 = 8
2nd h = 8 * 2 = 16
.... so on, just times 2

isaiah.feynman · Answer

$$x(t)=a \times b^{\frac{ \tau }{ t }}$$

isaiah.feynman · Answer

Use that formula.

anonymous · Answer

how do i use it

isaiah.feynman · Answer

Okay wait, I noticed I made a mistake the exponent is t/tau, NOT tau/t.

anonymous · Answer

ok
 so what do i plug in them

isaiah.feynman · Answer

t=8hours (convert to minutes!),  tau is 1 hour(convert to minutes!), b=2( the bacteria DOUBLES), and a=4

anonymous · Answer

1024? right?

isaiah.feynman · Answer

I didn't calculate it, but should be right. Who would make a mistake with such easy formula