There are seven green amoeba and three blue amoeba in a dish. Every minute, each amoeba splits into two identical copies; then, we randomly remove half the amoeba (thus there are always 10 amoeba remaining). This process continues until all amoeba are the same color. What is the probability that this color is green?
The answer is $70 \%$. Rather than considering the given colors, imagine the amoeba are colored with the following ten colors:

- Forest green
- Hunter green
- Jungle green
- Myrtle green
- Mint green
- Tea green
- Aqua green
- Sky blue
- Navy blue
- Midnight blue

Now, we simply wait until one of these particular shades becomes the only remaining shade. By symmetry, each shade has a $10 \%$ chance of being the sole survivor. Thus, the chance it is a "green" shade is $70 \%$.