In DS, how x>5 satisfies "is x>0"?

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how x>5 satisfies "is x>0"?

x>0 is-
Besides x is positive, x>0 also mean x could be 1/2, 1 ,2,3, 5, 100.

But x>5 means x could only be anything greater than 5, i.e. 5.5, 6, 10, but not 1, 2,3, 4.

So how does x>5 satisfies "is x>0"? (It was in one of the Beat the GMAT videos)

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by [email protected] » Fri Sep 18, 2015 9:13 am
Hi akshat.pant3,

The answer to a DS question is based on the 'consistency' of the resulst. A 'sufficient' Fact is one that gives you enough information to lead to a consistent result/answer.

As an example....
If a DS question asks "Is X > 0?", then THAT question is what we have to 'measure' our work against...

1) X^2 = 36

Here, X could be two different values: 6 or -6. With "6", the answer to the question is YES. With "-6", the answer to the question is NO. Those answers are INCONSISTENT, so Fact 1 is insufficient.

2) X > 5

Here, we know that X MUST be greater than 5, so regardless of what value(s) you make X, they are ALL greater than 0, so the answer to the question is ALWAYS YES and Fact 2 is sufficient.

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by [email protected] » Sun Sep 20, 2015 3:02 am
[email protected] wrote:Hi akshat.pant3,

The answer to a DS question is based on the 'consistency' of the resulst. A 'sufficient' Fact is one that gives you enough information to lead to a consistent result/answer.

As an example....
If a DS question asks "Is X > 0?", then THAT question is what we have to 'measure' our work against...

1) X^2 = 36

Here, X could be two different values: 6 or -6. With "6", the answer to the question is YES. With "-6", the answer to the question is NO. Those answers are INCONSISTENT, so Fact 1 is insufficient.

2) X > 5

Here, we know that X MUST be greater than 5, so regardless of what value(s) you make X, they are ALL greater than 0, so the answer to the question is ALWAYS YES and Fact 2 is sufficient.

GMAT assassins aren't born, they're made,
Rich

Yes, I got it till that point. However, where I'm confused is:
If x>0 then x can be 1,2,3,4,5 and also 6,7..
But x>5 only satisfies 6,7...but cannot satisfy if x=1,2,3,4,5

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by [email protected] » Sun Sep 20, 2015 9:25 am
Hi akshat.pant3,

You have to differentiate between the QUESTION that is asked and the INFORMATION that you're given.

If a question asks "Is X > 0?", then that does NOT provide any information - it's just a question. Until you know more about "X", there is no way to answer the question.

Once you learn that X > 5, THEN you can answer the question (and the answer is ALWAYS YES, since any number that is greater than 5 is also greater than 0).

GMAT assassins aren't born, they're made,
Rich
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