GMAT PREP QUESTION--

[venkat_yj]

Question- "m" is divisible by how many Prime numbers? So for any given value of m that fits the conditions, how many prime numbers would it take to divide m. (question is not asking you to count the number of possible m's that fit the conditions)

With condition (1)- m can be any one of odd numbers between 3 and 30- 5,7,11,13,17,19,23,25,29

So m is divisible by only one prime number. (so the answer conclusively is ONE)

With condition (2)- m can be any one of- 3,7,9,11,13,17,19,21,23,27,29
m is divisible by either one or two prime numbers. (for e.g what if m=21, divisible by two primes. So we cannot conclusively say ONE or TWO)

[venkat_yj]

Regarding level of difficulty, this is probably an 80th percentile question. Now i'm winging it :-)

[RonPurewal]

yes.

when a variable (such as "m" in this problem) can take on any of a multitude of different values, you have to consider the possibilities for ONE VALUE AT A TIME (i.e., you can't add up the possibilities across all values, as the original poster tried to do).