If a, b, and c are consecutive integers, such that a

Question

If a, b, and c are consecutive integers, such that a < b < c, is their sum even?

(1) abc = 0
(2) a + c = 0

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BrentGMATPrepNow · Answer

Given : a, b, and c are consecutive integer, such that a < b < c

Target question :    Is a + b + c EVEN?

Statement 1 : abc = 0  
This tells us that a = 0, b = 0 or c = 0
Here are two possible cases: 
 Case a : a = 0, b = 1 and c = 2. In this case, a + b + c = 0 + 1 + 2 = 3 (odd). So, the answer to the target question is  NO, a + b + c is NOT even 
 Case b : a = -1, b = 0 and c = 1. In this case, a + b + c = -1 + 0 +1 = 0 (even). So, the answer to the target question is  YES, a + b + c IS even 
Since we cannot answer the  target question  with certainty, statement 1 is NOT SUFFICIENT

Statement 2 : a + c = 0 
We already know that a, b, and c are consecutive integers, AND a < b < c
So, if a + c = 0, we can be certain that a = -1, b = 0 and c = 1
In this case, a + b + c = -1 + 0 + 1 = 0 (even). So, the answer to the target question is  YES, a + b + c IS even 
Since we can answer the  target question  with certainty, statement 2 is SUFFICIENT

Answer: B

Cheers,
Brent

rajatchopra1994 · Answer

Dear  GMATPrepNow  ,
In Statement 1, It is given : abc=0
In your case b, You have taken values,a = 1, b = 2 and c = 3 Which cannot be Zero, if we multiply them.
Hope you Got my point, Pls explain if i'm wrong.

Regards,
Rajat Chopra

BrentGMATPrepNow · Answer

Oops, the catch!
I've edited my response accordingly.
Kudos for you!!!!

Cheers, 
Brent

MHIKER · Answer

(1) 0 <1 < 2, abc is 0 but the sum is not even, -4<-2 < 0, abc is 0 and the sum is even. Insufficient.

(2) a+c =0 so must be -1 <-0<1, sufficient.

The answer is B

dassunil · Answer

Hello,

In the question if we know for sure that B=0 that means we are considering statement 1 as well. Because from statement 2 alone,would not help us reach the solution. For example C= 2 and A=-2 and any value of B 
I am quite new to GMAT methodology of thinking...
Please suggest where I went wrong and why this cannot be C.

Regards

bumpbot · Answer

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