A culture that doubles

A single cell is put in fresh food. It divides by binary fission every $30$ minutes, and every daughter cell does the same. You will list the number of cells after each hour, find when the culture first has more than $500$ cells, and compare two times.

The idea. In $h$ hours there are $\dfrac{60h}{30}$ divisions, and each division doubles the cells, so there are $2$ to the power of that number.

Your tasks.

1. Set cells to the number of cells after each hour in hours.
2. Set first_over to the first hour at which there are more than $500$ cells.
3. Set ratio to how many times more cells there are after $5$ hours than after $2$ hours.