Question 18
$N$ is a whole number and exactly three statements below are true.
(1) $N$ is prime.
(2) $N+3$ is prime.
(3) $1<\sqrt N<9$.
(4) $N+5$ has an odd number of positive factors.
How many values of $N$ are possible?
(1) $N$ is prime.
(2) $N+3$ is prime.
(3) $1<\sqrt N<9$.
(4) $N+5$ has an odd number of positive factors.
How many values of $N$ are possible?