Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized for You

we will pick new questions that match your level based on your Timer History

Track Your Progress

every week, we’ll send you an estimated GMAT score based on your performance

Practice Pays

we will pick new questions that match your level based on your Timer History

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

Thank you for using the timer!
We noticed you are actually not timing your practice. Click the START button first next time you use the timer.
There are many benefits to timing your practice, including:

Is M < 0? 1) -M = |-M| 2) M^2 = 9 [#permalink]
25 Feb 2010, 19:49

00:00

A

B

C

D

E

Difficulty:

5% (low)

Question Stats:

80% (01:26) correct
20% (00:40) wrong based on 10 sessions

Is M < 0?

1) -M = |-M| 2) M^2 = 9.

I kind of don't agree to the OE to this question. When 0 is neither positive nor negative such as +0 or -0 don't even exist then, what will be value of |0|? If so, can M ever be 0 at all, based on the equation given in stmt 1?

Let's then consider squaring on both sides, that leaves us with (M - M)(2M) = 0. So M essentially has to be 0, or absolutely anything, is the final output of the statement. Then M being +3 or -3 from stmt 2 does not solve our situation. M is anything from stmt 1, can be positive or negative and unsure of it's value even from stmt 2.

As per both my explanations above, E should have been the answer?
_________________

Re: M01, Question 17 on the GClub tests [#permalink]
25 Feb 2010, 21:32

Is M < 0?

1) -M = |-M| M<=0 -> any negative value of M, the equation holds good M=-3, RHS = 3 and LHS is 3. 0 coz if M=0, both sides are 0. Not sufficient 2) M^2 = 9. M=+3 or -3 Not sufficient

Combining M=-3

C

Barney - yes 0 is neither positive nor negative and you wont get a question asking what is |-0| .. but if a variable is given and the variable is of the kind y=-x, for all x, then for x=0, we say y = 0 --- do you say for x=0, there is no such value as -0 so this is INVALID? No right -- we can substitute 0 in a variable and it the value by chance comes up as -0, the value would be taken as 0.

Re: M01, Question 17 on the GClub tests [#permalink]
12 Mar 2010, 01:53

BarneyStinson wrote:

Is M < 0?

1) -M = |-M| 2) M^2 = 9.

I kind of don't agree to the OE to this question. When 0 is neither positive nor negative such as +0 or -0 don't even exist then, what will be value of |0|? If so, can M ever be 0 at all, based on the equation given in stmt 1?

Let's then consider squaring on both sides, that leaves us with (M - M)(2M) = 0. So M essentially has to be 0, or absolutely anything, is the final output of the statement. Then M being +3 or -3 from stmt 2 does not solve our situation. M is anything from stmt 1, can be positive or negative and unsure of it's value even from stmt 2.

As per both my explanations above, E should have been the answer?

stmt1: -M = |-M| there can be two cases -M = -M or -M = M => 2M = 0 => M= 0 So, M < 0 is not true

stmt2: M^2 = 9 => M = 3, -3 it is not suff not answering the question. Should not A be the answer of this question? |x| is actually the amount of x irrespective of its sign. Usually it is used to calculate distances on the coordinates. So, |0| means something with no value right?
_________________

Re: M01, Question 17 on the GClub tests [#permalink]
12 Mar 2010, 15:46

sidhu4u wrote:

BarneyStinson wrote:

Is M < 0?

1) -M = |-M| 2) M^2 = 9.

I kind of don't agree to the OE to this question. When 0 is neither positive nor negative such as +0 or -0 don't even exist then, what will be value of |0|? If so, can M ever be 0 at all, based on the equation given in stmt 1?

Let's then consider squaring on both sides, that leaves us with (M - M)(2M) = 0. So M essentially has to be 0, or absolutely anything, is the final output of the statement. Then M being +3 or -3 from stmt 2 does not solve our situation. M is anything from stmt 1, can be positive or negative and unsure of it's value even from stmt 2.

As per both my explanations above, E should have been the answer?

stmt1: -M = |-M| there can be two cases -M = -M or -M = M => 2M = 0 => M= 0 So, M < 0 is not true

stmt2: M^2 = 9 => M = 3, -3 it is not suff not answering the question. Should not A be the answer of this question? |x| is actually the amount of x irrespective of its sign. Usually it is used to calculate distances on the coordinates. So, |0| means something with no value right?

value of |0| is 0. inequality questions hinges on the 0 values a lot. so dont ignore those.