Practice Lecture - 55: Modular Arithmetic (7.2) - Lecture

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9 questions

Flashcard drill
4 cards from this section. Quick, good the night before a test.
Exercise
6 questions · about 4 min · pass mark 70%. Hints available.
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Quiz
3 questions · about 2 min · pass mark 70%. Hints available.
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6 sample questions

Question 1.
What is 7 mod 3?
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Think about how many times 3 can fit into 7.
Question 2.
Explain what it means for two numbers to be congruent modulo N.
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Consider the definition of congruence.
3Question 3.
What is the result of 10 mod 3?
- 1
- 2
- 3
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Sit down and think about how many times 3 goes into 10.
4Question 4.
Is the statement '6 ≡ 2 (mod 4)' true?
- True
- False
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Calculate 6 mod 4 and see if it equals 2.
Question 5.
Prove that if a ≡ b (mod N) and c is an integer, then a + c ≡ b + c (mod N).
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Rewrite a in terms of its congruence definition.
Question 6.
Find all integers x such that 2x ≡ 1 (mod 3).
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Try small integers and check their congruence.

5 more questions in this section. Enroll free to practise them all.