Vikingland Puzzle
Year 2000:
In the country of "Vikingland" assume there are people and they are equally distributed in gender, exactly 50% male and 50% female. Assume that there is an even number of people who are married (no one will have more than 1 wife) and everyone dies at the age 100. One day, the king of "Vikingland" heard a rumor that there is going to be an attack from his neighboring country "Astroland" in 30 years. Needing to defend the country he decided that he needed more warriors so he needed more men in the country. Therefore he issued a new law decree, "Woman can keep having babies as long as it is a boy, but once woman give birth to a girl they must stop having anymore babies for the rest of their lives." Some woman were really lucky, one of them even got 10 baby boys, while some woman were really unlucky that their first child was a girl!
Also assume that there is exactly 50/50 chance of getting a boy or a girl baby in Vikingland.
30 years later:
After 30 years, the king was told that there was not going to be an attack from the neighboring country "Astroland" because of some specific reason.
Can you assume that after 30 years, which gender will be more in the country "Vikingland"?
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1 solution
Each child born has a 50% chance to be a boy and a 50% chance to be a girl. It doesn't matter when couples stop having babies.
Think of it this way: Consider all the babies born in Vikingland in sequence. Every time a girl is born, that family stops having babies. But that doesn't affect the overall composition of the population! For example: BG|BBBG|G|BBBG|BG|G|BG|G|G|BB... (generated using an RNG).