GMAT Set 4 Q23

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GMAT Set 4 Q23

by Abhijit K » Wed Feb 18, 2015 1:31 am
Please help me solve Q23 in the attachment.

Thanks in advance.
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by Uva@90 » Wed Feb 18, 2015 7:18 am
Abhijit K wrote:Please help me solve Q23 in the attachment.

Thanks in advance.
Hi Abhijit,

Did you ever try this question ? what you have doubt in this question ?

It would be helpful if you post your doubts along with questions.


Regards,
Uva.
Last edited by Uva@90 on Wed Feb 18, 2015 7:34 am, edited 1 time in total.
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by Uva@90 » Wed Feb 18, 2015 7:22 am
Question states to find the answer of n+m = ?

Firstly what is n = e+y
Secondly what is m = d+z

So n+m = e+y+d+z(so you need e,y,d,z to know sum of n and m )

Stmt 1: d+y = -3
Insufficient since it doesn't give any info about e and z

Stmt 2: e+z = 12
Insufficient since it doesn't give any info about d and y

1+2
give all the values hence it is sufficient.

OA is C

Regards,
Uva
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by Brent@GMATPrepNow » Wed Feb 18, 2015 8:25 am
Image

The figure above shows two entries, indicated by m and n, in an addition table. What is the value of n + m?

(1) d + y = -3
(2) e + z = 12
Target question: What is the value of n + m?
Notice that the table tells us that m = d + z and that n = e + y
So, m + n = (d + z) + (e + y)
So we can REPHRASE the target question...
REPHRASED target question: What is the value of d + z + e + y?

Statement 1: d + y = -3
This information provides only half of the information we need.
We still need the values of z and e in order to find the sum of d + z + e + y
Since we cannot answer the REPHRASED target question with certainty, statement 1 is NOT SUFFICIENT

Statement 2: e + z = 12
This information provides only half of the information we need.
We still need the values of d and y in order to find the sum of d + z + e + y
Since we cannot answer the REPHRASED target question with certainty, statement 2 is NOT SUFFICIENT

Statements 1 and 2 combined
Statement 1 tells us that d + y = -3
Statement 2 tells us that e + z = 12
So, d + z + e + y = (d + y) + (e + z) = (-3) + (12) = 9
Since we can answer the REPHRASED target question with certainty, the combined statements are SUFFICIENT

Answer = C

Cheers,
Brent
Brent Hanneson - Creator of GMATPrepNow.com
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by Abhijit K » Thu Feb 19, 2015 12:39 am
Hello Uva,

I couldn't understand the addition matrix.Thanks for your help. Understood it now.


Regards,
Abhijit K.