Every 20 minutes, one bacterium divides into two. How many bacteria will be produced after two hours, if one starts with 10 bacteria?

The correct option is B $2^6\times 10$

According to the question, in a 20 minutes cycle, cells double. In 2 hours i.e 120 minutes there will be 6 cycles of 20 min each. If we start from 10 bacteria, then after 6 cycles of 20 minutes each (2 hours in total), we will have 10x 2^6 cells after 2 hours.

So, the correct answer is '2^6 x 10'.