Absolute Value (Manhattan Prep Question Bank)

[WilliamB305]

Hello,

This question has been copied/pasted in its entirety from the Number Properties question bank offered on this website. Can you please provide a different answer explanation? I am having difficulty understanding how A is not sufficient. The number used in the answer explanation for statement 1 makes "a" positive - shouldn't "a" be negative, therefore making "b" a larger negative giving us a definitive answer?


MANHATTAN PREP - NUMBER PROPERTIES QUESTION BANK
(The Greater of Absolutes (2))
Is |a| > |b|?

(1) b < -a

(2) a < 0

ANSWER: E
We can rephrase this question as: "Is a farther away from zero than b, on the number-line?" We can solve this question by picking numbers:

Since Statement 2 is less complex than Statement 1, begin with Statement 2 and a BD/ACE grid.

(1) INSUFFICIENT: Picking values that meet the criteria b < -a demonstrates that this is not enough information to answer the question.

a b Is |a| > |b| ?
2 -5
NO
-5 2
YES

(2) INSUFFICIENT: We have no information about b.

(1) AND (2) INSUFFICIENT: Picking values that meet the criteria b < -a and a < 0 demonstrates that this is not enough information to answer the question.

a b Is |a| > |b|?
-2 -5
NO
-5 2
YES

The correct answer is E.

Kind Regards,

William

[RonPurewal]

there's no reason to think "a" has to be negative, unless you're using statement 2.

in fact -- since statement TWO is the one that makes "a" negative, you should DEFINITELY think of both negative AND non-negative values of "a" when you consider statement ONE.
...in other words, when you see statement 2, you should think "oh hey, this is a restriction". and so, when you consider the OTHER statement (#1) by itself, you should think of it both with AND without that restriction.

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[RonPurewal]

this question is posted in the wrong folder (the MPrep non-CAT material has its own folder here), so, if you have further questions about this problem, please post them in the correct place.

thank you.