DS - Aboslute Values

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DS - Aboslute Values

by debmalya_dutta » Tue Sep 21, 2010 8:11 pm
source MGMAT CAT
Is there a quick way to solve this ?

If a and b are integers, and |a| > |b|, is a · |b| < a - b?

(1) a < 0

(2) ab is greater than or equal to 0

Has anyone come across any quick approach to this problem (not the one in the provided by MGMAT)
@Deb
Source: — Data Sufficiency |

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by selango » Tue Sep 21, 2010 9:23 pm
Quick approach is to plugin the values.

|a|>|b|

a · |b| < a - b?

stmt1,

a<0

We don't know value of b. b can be -ve,+ve or 0.

Insuff

stmt2,

ab>=0

a=1,b=0 -- a · |b| < a - b

a=3,b=2 -- a · |b| > a - b

Insuff

Combining 1 and 2,

a<0 and ab>=0

b is -ve or b=0

a=-3,b=-2 -- a · |b| < a - b

a=-3,b=0 -- a · |b| > a - b

Insuff

Pick E
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by debmalya_dutta » Wed Sep 22, 2010 10:47 am
thanks ...
@Deb