v and w GmatPrep

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v and w GmatPrep

by massi2884 » Mon Mar 19, 2012 12:19 pm
If v and w are different integers, does v=0?


statement 1: vw=v^2

statement 2: w=2

[spoiler]Statement 1 is sufficient because
vw=v^2
vw - v^2 = 0
v (w -v) = 0 but w is different from v so v=0
However, what if v=-3 and w=3 ? It should be (-3)(3)=9 and v wouldn't be zero.[/spoiler]

Could you please clarify? Thanks.
Source: — Data Sufficiency |

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by Anurag@Gurome » Mon Mar 19, 2012 8:08 pm
massi2884 wrote:If v and w are different integers, does v=0?


statement 1: vw=v^2

statement 2: w=2

[spoiler]Statement 1 is sufficient because
vw=v^2
vw - v^2 = 0
v (w -v) = 0 but w is different from v so v=0
However, what if v=-3 and w=3 ? It should be (-3)(3)=9 and v wouldn't be zero.[/spoiler]

Could you please clarify? Thanks.
(1) vw = v²
vw - v² = 0
v(w - v) = 0 implies either v = 0 or v = w
But it is given that v and w are different integers, so v = 0; SUFFICIENT.

(2) w = 2 but nothing is given about v; NOT sufficient.

The correct answer is A.
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