The figure above shows two entries, indicated by m and n, in

Question

Untitled.png 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

BrentGMATPrepNow · Accepted Answer

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

RELATED VIDEO
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srp · Answer

C

Information from table:
d+z=m (1)
e+y=n (2)

need to find "m+n"

A: d+y=-3, INSUFF - no information about n
B: e+z=12, INSUFF - no information about m

Adding 1 and 2 (under information)

(d+y)+(e+z)=m+n=12-3=9 (use both A and B)

Anonamy · Answer

There must be something I'm completely unaware of because how does box DY and box EZ relate to the box values the question asks for?

Bunuel · Answer

It's an an addition table. For example, e + y = n and d + z = m.

Hope it's clear.

MathRevolution · Answer

Forget conventional ways of solving math questions. In DS, Variable approach is the easiest and quickest way to find the answer without actually solving the problem. Remember equal number of variables and independent equations ensures a solution.

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
 
When you modify the original condition and the question, n+m=(e+y)+(d+z)=(e+z)+(y+d)=?. Then you need all 1) & 2) and therefore the answer is C.

 Once we modify the original condition and the question according to the variable approach method 1, we can solve approximately 30% of DS questions.

DHAR · Answer

Hi  Bunuel : Can you please post similar problems on addition tables

Bunuel · Answer

Check other  Addition/Subtraction/Multiplication Tables  problems from our  Special Questions Directory

geo1230 · Answer

Hello. Why do we need both statements? Doesn't statement 2 suffice? Since we need to find n+m we can just find e+z which is given in statement 2. Am I missing something here? The addition/multiplication works only with the variables in the first row/column? Thanks.

niks18 · Answer

Hi  geo1230

e+z will give you entry for row below m or column beside n. These are entries against different additions and does not simply signify the value of row or column.

so to get the value of n you need e+y and for m you need d+z

geo1230 · Answer

To be honest I still don't get it. If e+y gives me n and d+z gives me m, then, likewise e+z should give the value of the cell that is below m and right next to n, which is the same as saying n+m.

amanvermagmat · Answer

Hi

The highlighted part above is correct, but part after that is not correct. How is that cell equal to sum of n+m?

geo1230 · Answer

Hello. I thought it worked like a coordinate system. For example, the value of the sum e+y is located in the cell where n is located which is the intersection of row e and column y. So the value of n+m is the cell where they intersect, so it can be found from the row e and column z, as in e+z. In the picture I am trying to show what I mean. With red is the logic of the sums, with yellow the target cells where the value of the sum is located and with blue is the reason I believe that statement 2 alone is sufficient. Hope it clarifies the line of thinking.

amanvermagmat · Answer

Hi Geo

Thanks for clarifying where you were coming from. But this table is NOT to be interpreted like this. Rather it is to be interpreted in the way I have depicted in the attached pic.

So, as you can see, 'n' is e+y and 'm' is d+z. But that third cell is just 'e+z', its NOT 'n+m'.

geo1230 · Answer

amanvermagmat  Thank you for taking the time to clarify this. Now it's quite logical why my line of thinking is wrong. It's just that we don't have multiplication/addition tables in my country, so I bumped into these now with the GMAT. Thanks again and take a kudos as a thank you from me.

CharlessssCXY · Answer

But doesn't d+y added with 1 gives m? And e+z subtracted from 1 n?

AnkurGMAT20 · Answer

Bunuel , this one as well appear in Official Mock. Please tag this under GMAT Prep

Bunuel · Answer

_________________________
Added the tag. Thank you!

bumpbot · Answer

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The figure above shows two entries, indicated by m and n, in

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