Answer: There are 16 cells in the bottle at 10:20 a.m.
Explanation:
Since we have given that
Number of microscopic bacteria cells in the bottle at 10:05 A.M. = 2
At 10:15 a.m.
Number of cells in the bottle = 8
Each 5 minutes bacteria get multiplied by 2
So, in the beginning i.e. 10:05 a.m. , there were 2 bacteria,
after 5 minutes i.e. 10:10 a.m., there were

After next 5 minutes i.e. 10:15 a.m., there were

After next 5 minutes i.e. 10:20 a.m. ,there were

Hence, there are 16 cells in the bottle at 10:20 a.m.