Posted by Amy on Monday, December 21, 2009 at 12:34am.
The population of a particular type of bacteria doubles in number every 12 hours.
a)if there are 8 bcteria initially, write an equation that models the number of bacteria present after x 12 hours.
b)How many bacteria will be present after 5 days?
by using this formula N(t)=N0(1+r)2
The 0 is a small o on the bottom. i could be wrong with the formula.

PreCalculus  Reiny, Monday, December 21, 2009 at 1:24am
Since this is a "doubling" process, I would use
N(t) = 8(2)^(t/12) where t is in hours
b) so after 5 days or 120 hours,
N = 8(2)^120/12
= 8192