DS - factor

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DS - factor

by Xbond » Sun Oct 04, 2009 7:33 am
Hi there,

Could you help me to resolve this DS and explain the steps of resolution

Is the positive integer j divisible by a greater number of different prime numbers that the positive intger K ?

1) j is divisible by 30
2) k = 1000
Source: — Data Sufficiency |

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by boazkhan » Thu Feb 11, 2010 11:40 am
Is the answer C?

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by ajith » Thu Feb 11, 2010 11:44 am
Xbond wrote:Hi there,

Could you help me to resolve this DS and explain the steps of resolution

Is the positive integer j divisible by a greater number of different prime numbers that the positive intger K ?

1) j is divisible by 30
2) k = 1000
1) Alone is not sufficient because it doesnt talk about k at all
2) alone is not sufficient - no mention of j

Combining

k = 1000 = 2^3*5^3 = no of distinct prime factors 2
j = k*30 => k*2*3*5 = at least 3 distinct prime factors

Can answer the question whether positive integer j divisible by a greater number of different prime numbers that the positive integer K.

Hence C
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by Mom4MBA » Fri Feb 12, 2010 1:25 pm
Combining

k = 1000 = 2^3*5^3 = no of distinct prime factors 2
j = k*30 => k*2*3*5 = at least 3 distinct prime factors
Hi ajith here you took j = k*30, while j = h*30 where h can be <, = or > k, thus changing the number of prime factors accordingly, shouldn't the answer be E.

If I am wrong can you please further expand your explanation.
Thank you.
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by ajith » Fri Feb 12, 2010 1:33 pm
Mom4MBA wrote:
Combining

k = 1000 = 2^3*5^3 = no of distinct prime factors 2
j = k*30 => k*2*3*5 = at least 3 distinct prime factors
Hi ajith here you took j = k*30, while j = h*30 where h can be <, = or > k, thus changing the number of prime factors accordingly, shouldn't the answer be E.

If I am wrong can you please further expand your explanation.
Thank you.
I took j = k*30 , I should not have since k is featuring in the question, I should have taken as u have rightly pointed out j= h*30.

You are right in pointing out h is a variable and it can have more prime factors but the question is:

Is the positive integer j divisible by a greater number of different prime numbers that the positive intger K ?


j at least have 3 prime factors (it can be more than 3 also) while k has only 2 - It is sufficient to answer the question, isn't it?
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by Mom4MBA » Fri Feb 12, 2010 1:42 pm
Thanks ajith, you are right.

I got lost somewhere..:)
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by sanju09 » Fri Feb 12, 2010 10:20 pm
Xbond wrote:Hi there,

Could you help me to resolve this DS and explain the steps of resolution

Is the positive integer j divisible by a greater number of different prime numbers that the positive intger K ?

1) j is divisible by 30
2) k = 1000
I think the question line must read like: "by a greater number of different prime numbers than the positive integer k?"

(1) If j is divisible by 30, then j has at least 3 different prime numbers as its factors, namely 2, 3, and 5. No inkling of k to judge against. Insufficient

(2) If k is 1000, then k only and exactly has 2 different prime numbers as its factors, namely 2 and 5. No inkling of j to judge against. Insufficient

Taken together

With j having at least 3 different prime numbers as its factors and k having exactly 2 different prime numbers as its factors, disparity can be answered. Hence, sufficient

[spoiler]C[/spoiler]
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