DS2
This topic has expert replies
-
- Senior | Next Rank: 100 Posts
- Posts: 80
- Joined: Mon Jan 31, 2011 10:08 pm
- Followed by:2 members
GMAT/MBA Expert
- Brent@GMATPrepNow
- GMAT Instructor
- Posts: 16207
- Joined: Mon Dec 08, 2008 6:26 pm
- Location: Vancouver, BC
- Thanked: 5254 times
- Followed by:1268 members
- GMAT Score:770
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
-
- Senior | Next Rank: 100 Posts
- Posts: 80
- Joined: Mon Jan 31, 2011 10:08 pm
- Followed by:2 members
-
- Legendary Member
- Posts: 510
- Joined: Thu Aug 07, 2014 2:24 am
- Thanked: 3 times
- Followed by:5 members
Hi Brent ,Notice that the table tells us that m = d + z and that n = e + y
Thanks for the explanation , but one thing that i need to know is how do we come to know m= d + z and n= e + y.
GMAT/MBA Expert
- Brent@GMATPrepNow
- GMAT Instructor
- Posts: 16207
- Joined: Mon Dec 08, 2008 6:26 pm
- Location: Vancouver, BC
- Thanked: 5254 times
- Followed by:1268 members
- GMAT Score:770
The question assumes that we know how an addition table works. Here's a self-explanatory diagram:j_shreyans wrote:Hi Brent ,Notice that the table tells us that m = d + z and that n = e + y
Thanks for the explanation , but one thing that i need to know is how do we come to know m= d + z and n= e + y.
Cheers,
Brent