Question

If a bacteria reproduced every 5 minutes and you start with one at noon, how many will you have after one hour?

Answer 1

over 4,000 germs.

Answer 2

I will assume by "reproduced every 5 minutes"
you mean "double every 5 minutes)

so in one hour we would have a "doubling" taking place 12 times

noon -- 1
5 minutes later -- 2 , or 2^1 --- first doubling
10 minutes later --4 or 2^2 --- 2nd doubling
..
60 minutes later ---2^12 ------15th doubling

2^12 = 4096