Note that m is a odd integer between 2 and 30.prateek_guy2004 wrote:If m is a positive odd integer between 2 and 30, then m is divisible by how many different positive prime numbers?
(1) m is not divisible by 3.
(2) m is not divisible by 5.
how come 23 and 25 have the same number of unique prime factors?Anurag@Gurome wrote:Note that m is a odd integer between 2 and 30.prateek_guy2004 wrote:If m is a positive odd integer between 2 and 30, then m is divisible by how many different positive prime numbers?
(1) m is not divisible by 3.
(2) m is not divisible by 5.
Statement 1: Possible values of m are 5, 7, 11, 13, 17, 19, 23, 25 and 29. All of them have only one unique prime factor. Hence, whatever is the value of m, m is divisible by only one prime number.
Sufficient
Statement 2: Possible values of m are 3, 7, 9, 11, 13, 17, 19, 21 etc. For m = 21, m is divisible by two different prime numbers, 3 and 7. But for m = 3, 7, 9 etc, m is divisible by only one prime number.
Not sufficient
The correct answer is A.
what about 25, is also prime number?gmatboost wrote:You could get at the same answer a little faster by thinking about what m could be IF it is not prime (because if it is prime, the answer is always 1):
Statement 1:
The smallest m could be if it is odd, not prime, and not divisible by 3 is 5*7 = 35.
Too Big. M must be prime.
Statement 2
The smallest m could be if it is odd, not prime, and not divisible by 5 is 3*7 = 21.
In range. M may or may not be prime.
