A certain population of bacteria which demonstrates exponential growth doubles in size every 12 hours. If the initial population is 1,000 bacteria, what will be the population after 30 hours?

1 Answer
Jul 14, 2016

Population= 5,657

Explanation:

This is a Geometric progression with terms:

#T_1," " T_2," " T_3" " T_4 #
#1,000, 2,000, 4,000, 8,000 ....,#
#"0 hrs, 12 hrs, 24 hrs 36hrs.#

The first term, 'a' is 1,000.
The common ratio 'r' is 2.

The general term #T_n = ar^(n-1)#

The population after 30 hours, will be between the Third and 4th terms. #30/12 = 2.5#

Population =# 1000 xx 2^2.5 = 5,656.85#

However, we can't have 0.8 of a bacteria, so we would round to the nearest whole number.
Population= 5,657.