Number Properties - self modeled

[mbadream1]

1.
How many prime numbers between 1 and 20 are there in the set A. Set A={2,3,3,7,13,15,16,17,17}.

A: 7
b: 6
C: 5

2.
How many distinct prime numbers between 1 and 20 are there in the set A. Set A={2,3,3,7,13,15,16,17,17}.

A: 7
b: 6
C: 5

3.
How many prime factors of 63 are there in the set A. Set A={2,3,3,7,13,15,16,17,17}.

A: 3
b: 2

4.
How many distinct prime factors of 63 are there in the set A. Set A={2,3,3,7,13,15,16,17,17}.

A: 3
b: 2

The purpose of these questions is to understand the wordings in the qestion stem of an OG 12 problem. I modelled these questions on a question in OG 12. I am not sure if I can give the OG problem number because of copyright issues.

[tim]

Thanks for the post. The bottom line is that the kind of word traps you bring up in these questions just won't show up on the GMAT, so you won't need to worry about them for the most part. The one thing that might be relevant is this:

How many elements are in this set?
{1,2,2}
(answer is 3)

How many distinct elements are in this set?
{1,2,2}
(answer is 2)

As long as you know what "distinct" means, you should be fine with respect to any questions like yours the GMAT might ask.

[mbadream1]

Tim,

I definitely get what you are saying. But I just got an OG 12 question wrong as there was no proper wording in the question or may be I did not understand it correctly. I want to understand that, so I posted this question. That is why I modeled a question on OG 12 question and submitted.
Can you please answer the questions for me so that I can ask right questions?

[tim]

Actually, we make a point not to answer questions on the forums that are not relevant to the GMAT, because we want to help students focus on what's important for GMAT success. Can you give me an OG problem number that I can refer to so I can address your question in a more relevant context?

[mbadream1]

I am not sure how it is not related to GMAT. However, here is the OG question.
OG 12 Question 159.

[jlucero]

mbadream1, I see your point. Here's the key part of this problem- it limits you to the numbers in a certain set. For example, if I ask you how many numbers there are between 1 and 10, you'd say 10. Even though you can count the same numbers more than once. If I asked how many numbers between 1 and 10 are even, you'd say 5. If I asked how many numbers between 1 and 10 go into 100, you wouldn't count 2 twice, even though 100 has two 2's in its prime factorization. I agree it's a tad tricky, but I think it's well worded. This is a case of recognizing the way the GMAT consistently phrases things and learning from it.