[patapong]

Fun question! I think the following would be a viable strategy without communication:

Think of an observable criterion that matches the target distribution. For example, for 80-20:

- "Is the minute count higher than 12?" (This is the case in 80% of cases)

- "Do I have black hair?" (This is apparently also the case in 80% of cases)

Then, answer according to this criterion.

If everyone follows the same strategy, even if the criteria selected differs between each individual, the votes should match the target probability. Unless I am making a logical mistake :)