Question

PLEASE HELP ME!

The population of a bacteria in a Petri dish doubles every 12 hours. The population of the bacteria is initially 500 organisms.

How long will it take for the population of the bacteria to reach 800?

Answer 1

You want to know how long it'll take for the bacteria to grow
to (800/500) = 1.6 times their initial population.

The number of double-times it'll take is

[ log(1.6) / (log(2) ] = 0.6781 .

The double-time for these particular critters is 12 hours,
so it'll take them

0.6781 x 12 hours = 8.137 hours

= 8 hours 8.2 minutes .