A culture of bacteria doubles after 4 hours. If there are 8 g of bacteria to start with, how many are there after 8 hours and after 10 hours?

The bacteria grow at an exponential rate. If there are n g
to begin with, after 4 hours there are 2n g. The number of bacteria at any moment of
time can be expressed as x(t) = x0*(2)^(t/4)

Initially the
mass of the bacteria is 8 g, x0 = 8.

After 8 hours there
would be 8*(2)^(8/4) = 8*2^2 = 8*4 = 32 gram.

After 10
hours there would be 8*2^(10/4) = 8*2^(2.5) = 45.25 g
approximately.

After 8 hours we have 32 g of
bacteria and after 10 hours we have 45.25 g of
bacteria.