Practice General Results About Cardinality (4.3) - Module No # 05 - Discrete Mathematics

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6 sample questions

Question 1.
Define a countable set.
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Recall the definition based on matching with natural numbers.
Question 2.
What does the Cartesian product of two sets look like?
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Think of pairs like (a, b) from each set.
3Question 3.
What is a countable set?
- A set with elements that can be paired with natural numbers
- A finite set only
- A set without any elements
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Think of the relationship to natural numbers.
4Question 4.
True or False: The union of two countable sets is uncountable.
- True
- False
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Consider the properties of combining sets.
Question 5.
Prove that the set of all finite binary strings is countable.
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Start listing from zero length up to n length and order them.
Question 6.
Given two countable sets A and B, explain how to derive the sequence of elements in A union B.
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Think of how a zipper works to interlace elements.

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