A certain bacterium divides into 2 bacteria every 20 minutes. If there are four bacteria in the culture now, how many will there be in 4 hours, assuming that no bacteria die?

Answer 1

population doubles every 20 minutes, or 3 times per hour. So, every hour, the population grows by a factor of 8.

So, since we are starting at p(0) = 4,

p(h) = 4*8^h

gives the population after h hours.

p(4) = 4*8^4 = 4*4096 = 16384

Answer 2

X=N.2n
X=N.2(48)
X=N(24)
X=24