Practice Claim 2 (9.3) - Tutorial 5 - Discrete Mathematics

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6 sample questions

Question 1.
Define the term 'cardinality'.
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It's about counting elements.
Question 2.
How many elements are in the set of positive integers?
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Think about the positive integers themselves.
3Question 3.
What does cardinality refer to?
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It's about counting how many items are there.
4Question 4.
True or False: All infinite sets have the same cardinality.
- True
- False
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Think about the countable versus uncountable expanses.
Question 5.
Prove that the set of all rational numbers cannot be uncountable.
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Remember, rational numbers can be expressed in m/n format.
Question 6.
Show that the union of countable sets is countable using diagonalization.
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Check how elements can be indexed systematically.

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