If z is a positive integer, does z have more than 2 positive integer

Question

If z is a positive integer, does z have more than 2 positive integer factors?

(1) 23 < z < 29

(2) z is odd.

IanStewart · Answer

The question is just asking if z is not prime, and there are no primes strictly between 23 and 29, so Statement 1 is sufficient. Statement 2 is not, since some odd numbers are prime and some are non-prime, so the answer is A.

GMATBusters · Answer

If z is a positive integer, does z have more than 2 positive integer factors?:
the question can be reduced to  " is z a prime number " ?

1)23 < z < 29
z can be 24, 25, 26, 27, 28
as none of these possible values of z is prime, we can  definitely answer  that z is not a prime number .
 SUFFICIENT

2) z is odd: z can be any odd number : 3 or 9. hence it is  NOT SUFFICIENT  to answer whether z a prime number.

Answer = A

GMATinsight · Answer

CONCEPT : Prime Numbers have exactly 2 distinct factors. FIrst factor being 1 and the second factor being the number itself

Any positive integer other than prime numbers and 1 have greater than 2 factors

Question : does z have more than 2 positive integer factors?

Question REPHRASED : Is z a Prime Number?

Statement 1 : 23 < z < 29

i.e. z = {24, 25, 26, 27, 28} (because z is integer)
Not none of the possible values of z is a Prime number i,e, answer to teh question is is DEFINITELY NO hence
SUFFICIENT

Statement 2 : z is odd

i.e. z may be 3 (prime) or 15 (non-prime) hence
NOT SUFFICIENT

Answer: Option A

If z is a positive integer, does z have more than 2 positive integer

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