This task is about creating an unanswerable question based on a given passage. Construct a question that looks relevant to the given context but is unanswerable. Following are a few suggestions about how to create unanswerable questions:
(i) create questions which require satisfying a constraint that is not mentioned in the passage
(ii) create questions which require information beyond what is provided in the passage in order to answer
(iii) replace an existing entity, number, date mentioned in the passage with other entity, number, date and use it in the question
(iv) create a question which is answerable from the passage and then replace one or two words by their antonyms or insert/remove negation words to make it unanswerable.
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Question: Passage: One way to divide hunter-gatherer groups is by their return systems. James Woodburn uses the categories "immediate return" hunter-gatherers for egalitarian and "delayed return" for nonegalitarian. Immediate return foragers consume their food within a day or two after they procure it. Delayed return foragers store the surplus food (Kelly, 31).

Answer: What is the only way to divide hunter-gatherer groups?

Question: Passage: About 75% of the population is employed in subsistence agriculture upon Swazi Nation Land (SNL). In contrast with the commercial farms, Swazi Nation Land suffers from low productivity and investment. This dual nature of the Swazi economy, with high productivity in textile manufacturing and in the industrialised agricultural TDLs on the one hand, and declining productivity subsistence agriculture (on SNL) on the other, may well explain the country's overall low growth, high inequality and unemployment.

Answer: Where does the population get 75% of its income?

Question: Passage: The formation of the party was formally announced at Sydney Town Hall on 31 August 1945. It took the name "Liberal" in honour of the old Commonwealth Liberal Party. The new party was dominated by the remains of the old UAP; with few exceptions, the UAP party room became the Liberal party room. The Australian Women's National League, a powerful conservative women's organisation, also merged with the new party. A conservative youth group Menzies had set up, the Young Nationalists, was also merged into the new party. It became the nucleus of the Liberal Party's youth division, the Young Liberals. By September 1945 there were more than 90,000 members, many of whom had not previously been members of any political party.

Answer:
Where was the formation of the UAP party officially announced?