Number Properties Divisble Question

[shoumik]

Is pq divisble by 168?

1) p is divisble by 14.
2) q is divisble by 12.

I chose C because p and q are different and avoids redundancy. However, after searching google for a bit, I came to find out that the question posted on other forums is different from whats on my NP Guide. Particularly stmt 2; q should be p.

Is that true? If not, can someone explain how C is incorrect?

Thanks.

[atharshiraz]

Is pq divisble by 168?

1) p is divisble by 14.
2) q is divisble by 12.

I chose C because p and q are different and avoids redundancy. However, after searching google for a bit, I came to find out that the question posted on other forums is different from whats on my NP Guide. Particularly stmt 2; q should be p.

Is that true? If not, can someone explain how C is incorrect?

Thanks.

I am guessing this is from Data Sufficiency. And you are saying that both p and q are required to solve this.

You have to use the method of the prime factorization.
We have to show that pq/168 = integer value

In order to do that the prime factors of 168 must cancel all the prime factors of p and q (at the least).

The prime factors of 168 are 2, 2, 2, 3, 7

When we say that p/14 = int value it means that p has atleast 2 and 7 as prime factors.

The prime factors of p are 2, 7

When we say that q/12 = int value it means that q has atleast 2, 2 and 3 as prime factors.
The prime factors of q are 3 , 2, 2

So the fraction now looks like :
p(2,7) q(3 , 2, 2)
----------------
168(2,2,2,3,7)

So both p and q will be required to cover all the factors in 168.

Hence the answer is C.

[jnelson0612]

Is pq divisble by 168?

1) p is divisble by 14.
2) q is divisble by 12.

I chose C because p and q are different and avoids redundancy. However, after searching google for a bit, I came to find out that the question posted on other forums is different from whats on my NP Guide. Particularly stmt 2; q should be p.

Is that true? If not, can someone explain how C is incorrect?

Thanks.

shoumik, is this a specific question from our Number Properties strategy guide? If so, will you please provide a page number.