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?


AMO · AMO 2018 Secondary 1 (Grade 7)
