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Quiz: Number Theory

5 questionsNo time limitPass: 60%+10 XP on first pass

Divisibility and primes, the Euclidean and extended Euclidean algorithms, modular arithmetic rules, fast modular exponentiation, Fermat's little theorem, modular inverses, Euler's totient — and a complete toy RSA encryption built from them in Python.

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  1. Question 1

    What is gcd(252, 105)?

  2. Question 2

    Why do programming problems ask for answers "modulo 10^9 + 7"?

  3. Question 3

    When does a modulo m have a multiplicative inverse?

  4. Question 4

    What is φ(33)?

  5. Question 5

    In the toy RSA, what does the security of real RSA rely on?