After several failed searches for the question, I have decided to post it.
Don't know why [spoiler](1) /spoiler] is wrong.
If w + x is < 0, is w - y > 0?
(1) x + y < 0
(2) y < x < w
seems correct to solve this way:
combining stem (w+x < 0) with (1) - x+y<0, we have the 2 inequalities:
w + x < 0............(i)
x + y < 0.............(ii)
............................ SUBTRACTING (i) from (ii)
w - y < 0 If w<y, definitely w CANNOT be greater than y
(question asked) at the same time...SUFFICIENT
Correct response is NO "w is NOT > y" as asked.
(ii) I have no issues with that.
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If w + x is < 0, is w - y > 0?
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gmatdriller
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Rahul@gurome
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You cannot subtract inequalities like this. It's not equation! Only thing we know from question stem and statement 1 is both (w + x) and (x + y) is less than zero. We don't which one of them is greater than the other. When you're subtracting (x + y) from (w + x) it could be positive or negative. For example say, (w + x) = -4 and (x + y) = -7 => (w + x) - (x + y) = 3 > 0.gmatdriller wrote:After several failed searches for the question, I have decided to post it.
Don't know why [spoiler](1) /spoiler] is wrong.
If w + x is < 0, is w - y > 0?
(1) x + y < 0
(2) y < x < w
seems correct to solve this way:
combining stem (w+x < 0) with (1) - x+y<0, we have the 2 inequalities:
w + x < 0............(i)
x + y < 0.............(ii)
............................ SUBTRACTING (i) from (ii)
w - y < 0 If w<y, definitely w CANNOT be greater than y
(question asked) at the same time...SUFFICIENT
Correct response is NO "w is NOT > y" as asked.
(ii) I have no issues with that.
But we can add them and say (w + 2x + y) < 0, because there is no way addition of two negative number will result in a positive number.
Hope it helps.
Rahul Lakhani
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On MBA sabbatical (at ISB) for 2011-12 - will stay active as time permits
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Quant Expert
Gurome, Inc.
https://www.GuroMe.com
On MBA sabbatical (at ISB) for 2011-12 - will stay active as time permits
1-800-566-4043 (USA)
+91-99201 32411 (India)
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gmatdriller
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Rahul, i got it now.
While the differecnce between two negatives can be either positive or
negative, their sum is always negative.
Thanks.
Source: GMATPrep
OA is B.
While the differecnce between two negatives can be either positive or
negative, their sum is always negative.
Thanks.
Source: GMATPrep
OA is B.
Last edited by gmatdriller on Fri Dec 10, 2010 3:18 pm, edited 1 time in total.
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junegmat221
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@Rahul,
Can u please detail us on what are the strict guidelines to be followed ,
When dealing with inequalities like the one above.
Thanks..
Can u please detail us on what are the strict guidelines to be followed ,
When dealing with inequalities like the one above.
It would be of much help..You cannot subtract inequalities like this. It's not equation! Only thing we know from question stem and statement 1 is both (w + x) and (x + y) is less than zero. We don't which one of them is greater than the other. When you're subtracting (x + y) from (w + x) it could be positive or negative. For example say, (w + x) = -4 and (x + y) = -7 => (w + x) - (x + y) = 3 > 0.
Thanks..
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Rahul@gurome
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Always cases:junegmat221 wrote:@Rahul,
Can u please detail us on what are the strict guidelines to be followed ,
When dealing with inequalities like the one above.
It would be of much help..
Thanks..
- Positive + Positive = Always positive
Positive - Negative = Always positive
Negative - Positive = Always negative
Negative + Negative = Always negative
May be cases:
- Any combination other than those above are may be positive or negative.
Rahul Lakhani
Quant Expert
Gurome, Inc.
https://www.GuroMe.com
On MBA sabbatical (at ISB) for 2011-12 - will stay active as time permits
1-800-566-4043 (USA)
+91-99201 32411 (India)
Quant Expert
Gurome, Inc.
https://www.GuroMe.com
On MBA sabbatical (at ISB) for 2011-12 - will stay active as time permits
1-800-566-4043 (USA)
+91-99201 32411 (India)
