Hello
The approach I took for this problem
Statement 1
There are 3 variables and 2 equations. Hence we should be able to find the value of x and y.
So it should be sufficient to answer the Q.
It does not matches with the OA. Please help me with the problem. Thanks
Is x^2+y^2>3z?
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Hi melguy,
I'm going to give you a hint, then have you try this question again.
First, this is a YES/NO question; it's asking if x^2 + y^2 > 3z? It doesn't tell you ANYTHING about the variables. Second, is it possible that some (or all) of these variables = 0?
GMAT assassins aren't born, they're made,
Rich
I'm going to give you a hint, then have you try this question again.
First, this is a YES/NO question; it's asking if x^2 + y^2 > 3z? It doesn't tell you ANYTHING about the variables. Second, is it possible that some (or all) of these variables = 0?
GMAT assassins aren't born, they're made,
Rich
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It made the problem so easy! I broke down all the equations, testing with under roots and everything to see where the value of x^2 and y^2 is hiding but that surely is not the best method in this problem.[email protected] wrote: some (or all) of these variables = 0?
Thanks a lot Rich!
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Hi melguy,
There are ultimately 2 measures of "success" when choosing to answer a GMAT question:
1) Did you get the question correct?
2) How long did it take to do so?
If counting on your fingers is the fastest way that you can come up with to answer a question, then count on your fingers! Most GMAT questions have several potential approaches to solving, so flexibility on your part is a must (especially if you want to develop strong pacing skills). With what you've just learned, was the question made faster and easier to solve? Then remember these ideas the next time you face a similar question.
GMAT assassins aren't born, they're made,
Rich
There are ultimately 2 measures of "success" when choosing to answer a GMAT question:
1) Did you get the question correct?
2) How long did it take to do so?
If counting on your fingers is the fastest way that you can come up with to answer a question, then count on your fingers! Most GMAT questions have several potential approaches to solving, so flexibility on your part is a must (especially if you want to develop strong pacing skills). With what you've just learned, was the question made faster and easier to solve? Then remember these ideas the next time you face a similar question.
GMAT assassins aren't born, they're made,
Rich
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Just to add on a more general area - Ideally you need to have X number of distinct equations to solve for X variables.melguy wrote:Hello
Statement 1
There are 3 variables and 2 equations. Hence we should be able to find the value of x and y.
So it should be sufficient to answer the Q.
Statement 1 is clearly not sufficient as it has only 2 variables.
I think you took the question stem as an equation.
A good question also deserves a Thanks.
Messenger Boy: The Thesselonian you're fighting... he's the biggest man i've ever seen. I wouldn't want to fight him.
Achilles: That's why no-one will remember your name.
Messenger Boy: The Thesselonian you're fighting... he's the biggest man i've ever seen. I wouldn't want to fight him.
Achilles: That's why no-one will remember your name.
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I should point out that the question isn't asking us to find the individual values of x, y and z. So, the rule about needing K different equations to solve a system with K variables doesn't apply here. Also, the question features inequalities, which also negates the rule.melguy wrote:
There are 3 variables and 2 equations. Hence we should be able to find the value of x and y.
For example, let's leave the target question as is (Is x^2 + y^2 > 3z?)
If statement 2 were "z < 0," then we'd have sufficient information to answer the target question. Here's why:
If z < 0, then 3z is negative
x^2 + y^2 will always be greater than or equal to zero.
So, it must be true that x^2 + y^2 > 3z
Cheers,
Brent
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OA should be CMission2012 wrote:Is OA A
Statement 1 cannot be sufficient.
Statement 1 is true when x = y = z = 0 which would not satisfy the question stem.
Statement 1 is true when x = 2 ; y = 0 and z = 1/9 which would satisfy the question stem.
A good question also deserves a Thanks.
Messenger Boy: The Thesselonian you're fighting... he's the biggest man i've ever seen. I wouldn't want to fight him.
Achilles: That's why no-one will remember your name.
Messenger Boy: The Thesselonian you're fighting... he's the biggest man i've ever seen. I wouldn't want to fight him.
Achilles: That's why no-one will remember your name.