jmc

Question

Joe is studying a bacteria population. There are 20 bacteria present at 3:00 p.m. and the population doubles every 3 minutes. Assuming none of the bacteria die, how many bacteria are present at 3:15 p.m. the same day?

Accepted Answer

There are five 3-minute increments between 3:00 pm and 3:15 pm, so the bacteria doubles 5 times, so the final population is 2^5 = 32 times the initial population. Hence at 3:15 pm there are 20 32 = 640 bacteria.