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Source: — Data Sufficiency |
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by cans » Tue Sep 20, 2011 2:55 am
IF ab/cd>0 is bc>cd???
B) b<c<0.
as c is less than 0, we have to find if b<d???
as b<0, then proving that d>0 will be sufficient.
ab/cd >0 and both b,c are less than 0, thus a/d >0. now if a<0, d<0
And thus insufficient
I don't think b is the ans..
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by tttrn333 » Tue Sep 20, 2011 3:12 am
E right?
cans wrote:IF ab/cd>0 is bc>cd???
B) b<c<0.
as c is less than 0, we have to find if b<d???
as b<0, then proving that d>0 will be sufficient.
ab/cd >0 and both b,c are less than 0, thus a/d >0. now if a<0, d<0
And thus insufficient
I don't think b is the ans..
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by Ian Stewart » Tue Sep 20, 2011 8:26 am
tttrn333 wrote:IF ab/cd>0 is bc>cd?

1) cd>ab
2) b<c<0

I don't understand how B is sufficient.
Yes, the answer is E, not B. We could have, using both statements, either of the following scenarios:

a = 4, b = -3, c = -2, d = 1

or

a = -1, b = -3, c = -2, d = -4

In the first case bc is greater than cd, and in the second bc is less than cd.
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by dgarla » Fri Sep 23, 2011 7:45 am
Yes, the answer is E, not B. We could have, using both statements, either of the following scenarios:

a = 4, b = -3, c = -2, d = 1

or

a = -1, b = -3, c = -2, d = -4
In the first case bc is greater than cd, and in the second bc is less than cd.
The bolded example does not qualify the primary assumption of ab/cd>0.
Correct me if i am wrong.
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by mehrasa » Fri Sep 23, 2011 10:43 am
to me the answer is B

rephrase the Q stem: we are asked to say whether bc>cd?????? this is equivalent to find whether b>c??

1) not sufficient
2)b<c<0 this otion explicitely say that b<c on the other hand c<0==> we can answer "yes" to the Q ==> sufficient
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by Ian Stewart » Fri Sep 23, 2011 11:53 am
dgarla wrote:
Yes, the answer is E, not B. We could have, using both statements, either of the following scenarios:

a = 4, b = -3, c = -2, d = 1

or

a = -1, b = -3, c = -2, d = -4
In the first case bc is greater than cd, and in the second bc is less than cd.
The bolded example does not qualify the primary assumption of ab/cd>0.
Correct me if i am wrong.
If all four of the quantities a, b, c and d, are negative, then ab is positive and so is cd, so ab/cd is certainly positive. So yes, the example given satisfies the condition in the question.
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by shubhamkumar » Tue Mar 27, 2012 8:52 pm
This is a problem from Kaplan CAT#1, you put the question stem wrong.
The actual question is IF ab/cd<0 is bc>ad?
tttrn333 wrote:IF ab/cd>0 is bc>cd?

1) cd>ab
2) b<c<0

I don't understand how B is sufficient.
Under the corrected circumstances the stem implies that either only ab is negative or only cd is negative in the above question.Statement 2 tells that b and c are both negative, which implies that to satisfy the question stem, either of a or d will have to be negative to make expression ab/cd < 0.In either case ad will be negative which will be less than bc given that b and c are both negative as per statement 2.
Please correct the question.
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