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If abcd ≠ 0, is ab2c3d4 < 0?

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Intern
Joined: 02 Oct 2013
Posts: 29
Location: India
Concentration: Marketing, General Management
Schools: Haas '18
GMAT Date: 07-20-2014
If abcd ≠ 0, is ab2c3d4 < 0?  [#permalink]

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01 Mar 2014, 05:26
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Difficulty:

35% (medium)

Question Stats:

77% (00:32) correct 23% (00:49) wrong based on 57 sessions

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If abcd ≠ 0, is $$ab^2c^3d^4 < 0 ?$$

(1) $$ab^2c^3 < 0$$

(2) $$b^2c^3d^4 < 0$$

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Re: If abcd ≠ 0, is ab2c3d4 < 0?  [#permalink]

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01 Mar 2014, 05:36
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Anshulmodi wrote:
If abcd ≠ 0, is $$ab^2c^3d^4 < 0 ?$$

(1) $$ab^2c^3 < 0$$

(2) $$b^2c^3d^4 < 0$$

If abcd ≠ 0, is $$ab^2c^3d^4 < 0$$?

Is $$ab^2c^3d^4 < 0$$? divide by $$b^2c^2d^4$$: is $$ac<0$$?

We can safely reduce by b^2c^2d^4, since this expression will always be positive: the square of a number is always non-negative plus we know that neither of the unknowns is zero, hence b^2c^2d^4>0

(1) $$ab^2c^3 < 0$$ --> divide by $$b^2c^2$$: $$ac<0$$. Sufficient.

(2) $$b^2c^3d^4 < 0$$ --> divide by $$b^2c^2d^4$$: $$c<0$$. We need to know the sign of a. Not sufficient.

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Re: If abcd ≠ 0, is ab2c3d4 < 0?  [#permalink]

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28 Jul 2018, 08:15
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Re: If abcd ≠ 0, is ab2c3d4 < 0? &nbs [#permalink] 28 Jul 2018, 08:15
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