Question

If the number of bacteria in a colony doubles every 9 hours and there is currently apopulation of 10,000 bacteria, what will the population be 18 hours from now?

Answer 1

After 9 hours, the population of the bacteria will be twice the initial population, it means:

$2\cdot10000=20000$

After other 9 hours, the population will be two times 20000, it means:

$2\cdot10000=40000$

According to this, after 18 hours the population of the bacteria will be 40000.