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AMO 2018 Secondary 1 (Grade 7) Question 23

AMO · AMO 2018 Secondary 1 (Grade 7)

Question 23

$N$ is a whole number, and exactly three of these statements are true: (1) $N$ is prime; (2) $N+3$ is prime; (3) $1<\sqrt N<7$; (4) $N+5$ has an odd number of positive divisors. How many possible values of $N$ are there?

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