Question

A bacteria culture begins with 15 bacteria which double in amount at the end of every hour. How many bacteria exist in the culture at the end of the 12th hour?

Answer 1

@SolomonZelman @kc_kennylau

Answer 2

@Disco619

Answer 3

After every hour it doubles

1st hour- 15*2 =30
2nd hour-(15*2)*2=15*\(15*2^{2}\)=60
3rd hour-(15*2*2)*2=\(15*2^{3}\)=120
4th hour-(15*2*2*2)*2=\(15*2^{4}\)=240

so after 12th hour
\(15*2^{12}\)

Answer 4

Im not really good at these "arithmetic progression" equations but the answer is:
61440

Answer 5

@kc_kennylau where does the n-1 come from?

Answer 6

@kc_kennylau after first hour it will double

Answer 7

We are not gonna count the 15 bacteria. They don't come in the 12 hours. They are the beginning