DS / xz = 0

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DS / xz = 0

by Xbond » Sat Aug 29, 2009 8:00 am
Hi there,

Could you explain in the simplest this concept and how to resolve it

If z is a positive number, is xz = 0?
(1) xz = -3x
(2) xz = 3x
Source: — Data Sufficiency |

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by real2008 » Sat Aug 29, 2009 9:21 am
is it C

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by ShikenO/kau » Sat Aug 29, 2009 9:29 am
If z is a positive number, is xz = 0?
(1) xz = -3x
(2) xz = 3x

It is given that Z is positive

Statement I:

xz = -3x
The possibilities are
1.z= -3 and x can be any value
But z is a positive number and this can be omitted
2.z=3 and x=-x
This condition is possible only when x =0

So we can say that xz= 0 with statement I


Statement II

xz=3x
The only possibility is z= 3 and x can have any value
This statement is insufficient

The answer is A

Please post the answer.

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by Xbond » Sat Aug 29, 2009 9:29 am
explanation please

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by Xbond » Sun Aug 30, 2009 8:02 am
oa is A