Question

Under favorable conditions, bacteria can multiply every 20 minutes. Starting with one bacteria cell, how many bacteria should you expect after 15 hours? Hint: Under favorable conditions, if one bacterium becomes 2 in 20 minutes (1 multiplied by 2), those 2 become 4 in the next 20 minutes, and then those 4 become 8 in the next 20 minutes. That means that 8 bacteria resulted in 1 hour. Now calculate the growth of bacteria for 15 hours.

Answer 1

Starting with one bacteria, we will have 8 bacteria in 1 hour. After that we will have 15 - 1 = 14 hours more. In 1 hour we have 3 times 20 minutes ( bacteria can multiply every 20 minutes ). 14 x 3 = 42. It means that there are 42 periods of 20 minutes more.
The number of bacteria after 15 hours:
8 x 2^(42) = 2^(45) = 35,184,372,088,832.