If bacteria foubles every 20 minutes how much bacteria will there be after 4 hours

4096 bacteria.

Step-by-step explanation:

If you start with one bacteria, and it doubles every 20 minutes, you would have 1*2^12 (Where 12 is every 20 minutes for 4 hours). 2^12 is 4096, so you would have 4096 bacteria after 4 hours.