Practice Set S With Single 1 (9.5.2) - Tutorial 5 - Discrete Mathematics

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6 sample questions

Question 1.
Define cardinality in your own words.
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Think about how many elements can fit in the set.
Question 2.
What is an injective function?
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Consider the idea of pairing items uniquely.
3Question 3.
What does cardinality measure?
- Size of a set
- Quality of a set
- Type of elements
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Think about what you are counting.
4Question 4.
Is it possible for an infinite set to have a cardinality less than א₀?
- True
- False
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Look back at the definitions of infinite sets.
Question 5.
Prove that the union of two countably infinite sets is countably infinite with an example.
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Think about merging two sequences while maintaining order.
Question 6.
Explain why a subset of positive integers cannot be both finite and uncountably infinite.
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Review definitions of finite and infinite sets.

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