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Gmat prep 2 - Numbers properties

This topic has 1 expert reply and 5 member replies

Gmat prep 2 - Numbers properties

Post
HI,

Can someone help me with this ...

If mv0?

(1) m

(2) m<0

tks,

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Senior | Next Rank: 100 Posts Default Avatar
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I think answer is B.

Rephrase the question. What is the sign of m or p? Since mv and pv are negative, either mv must be +- or -+ and pv must be +- or -+ to make a negative product and adhere to the restrictions in the stem.

1) m


2) m<0 - Sufficient. Knowing that m is negative allows us to conclude that v is positive.

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In order for mv and pv to be less than 0, we have one of two cases:
1) v < 0 (and m>0, p>0)
or
2) m<0 and p<0 (and v>0)
The reason is that a negative number is the product of a positive number and a negative number.

Statement 1 tells us that m
Statement 2 tells us that m<0. So, we know we have "case 2", ie that v>0. So, statement 2 is sufficient and the answer is B.

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Tatiana Becker | GMAT Instructor | Veritas Prep

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HI,

The OA is D.

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Thanks for catching my mistake-

I now see how 1) is sufficient.

consider:

for mv
Ex:

If m and p are positive then you can have 2*-1 < 3*-1 < 0 which violates the restriction that mp
If m and p are negative then you can have -2*1 < -1*1 < 0 which satisfies all restrictions.

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is it a right approach, someone please let me know.

mv
(m-p)v<0

stmt 1 says m

0

stmt 2 says m<0 given mv<0 hence v>0.

ANS D.

regards,


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Cubicle Bound Misfit

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GMAT/MBA Expert

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cubicle_bound_misfit wrote:
mv
(m-p)v<0

stmt 1 says m

0

stmt 2 says m<0 given mv<0 hence v>0.

ANS D.

regards,

cubicle_bound_misfit wrote:
is it a right approach, someone please let me know.
Yes, excellent approach- nicely done.

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