Praet read the question and please note that it is: Is the positive integer n equal to the square of an integer?..From statement 1 we know that for every prime number p if p is a divisor of n then so is p^2..so n could be 4,9 but n could be 18 or 50, for example, which makes statement 1) insufficient since we can not say if n is a square of an integer
you miss the p^2 part.
let me rephrase.
1. If n is divisible by p, it is divisible by p^2 too.
you have to satisfy the above requirement.
18 is divisible by 2 , but not divisible by 2^2.
so 18 does NOT satisfy the requirement of statement 1.
Do NOT violate the FACT in (1).