Please, one more:
thanks
Silvia
if x, y, and z are integers
This topic has expert replies
- Stuart@KaplanGMAT
- GMAT Instructor
- Posts: 3225
- Joined: Tue Jan 08, 2008 2:40 pm
- Location: Toronto
- Thanked: 1710 times
- Followed by:614 members
- GMAT Score:800
Hi,
please type out the questions rather than adding them as an attachment - it saves the people replying the work of typing them out, since you really need to look at the question to discuss it.
If x, y and z are integers, is x + y + 2z even?
Step 1 of the Kaplan Method for DS: Analyze the Stem
We see "is", we think "yes/no question: a definite yes is sufficient, as is a definite no; a "maybe" or "sometimes" is insufficient".
Since x, y and z are integers, 2z is always going to be even. So, we can simplify the question to:
Is x + y even?
Step 2 of the Kaplan Method for DS: Evaluate the Statements
(1) x + z is even.
No info about y, insufficient.
(2) y + z is even.
No info about x, insufficient.
Together:
We can write each statement as an equation:
x + z = even
y + z = even
and then add them together:
x + z + y + z = even + even
simplifying both sides:
x + y + 2z = even
Hey! That's exactly what the question is asking - so that's a definite "yes", sufficient. Choose (C).
please type out the questions rather than adding them as an attachment - it saves the people replying the work of typing them out, since you really need to look at the question to discuss it.
If x, y and z are integers, is x + y + 2z even?
Step 1 of the Kaplan Method for DS: Analyze the Stem
We see "is", we think "yes/no question: a definite yes is sufficient, as is a definite no; a "maybe" or "sometimes" is insufficient".
Since x, y and z are integers, 2z is always going to be even. So, we can simplify the question to:
Is x + y even?
Step 2 of the Kaplan Method for DS: Evaluate the Statements
(1) x + z is even.
No info about y, insufficient.
(2) y + z is even.
No info about x, insufficient.
Together:
We can write each statement as an equation:
x + z = even
y + z = even
and then add them together:
x + z + y + z = even + even
simplifying both sides:
x + y + 2z = even
Hey! That's exactly what the question is asking - so that's a definite "yes", sufficient. Choose (C).
Stuart Kovinsky | Kaplan GMAT Faculty | Toronto
Kaplan Exclusive: The Official Test Day Experience | Ready to Take a Free Practice Test? | Kaplan/Beat the GMAT Member Discount
BTG100 for $100 off a full course
- Stuart@KaplanGMAT
- GMAT Instructor
- Posts: 3225
- Joined: Tue Jan 08, 2008 2:40 pm
- Location: Toronto
- Thanked: 1710 times
- Followed by:614 members
- GMAT Score:800
Oh, and hey - please post in the right forum (this is a data sufficiency question, not problem solving!).
Stuart Kovinsky | Kaplan GMAT Faculty | Toronto
Kaplan Exclusive: The Official Test Day Experience | Ready to Take a Free Practice Test? | Kaplan/Beat the GMAT Member Discount
BTG100 for $100 off a full course
-
- Master | Next Rank: 500 Posts
- Posts: 126
- Joined: Wed Jun 24, 2009 1:12 pm
- Location: Montreal
- Thanked: 2 times
- GMAT Score:510
Hi Stuart:Stuart Kovinsky wrote:Oh, and hey - please post in the right forum (this is a data sufficiency question, not problem solving!).
Yes 1, I should have typed the question, in fact, I did it on the first one I poested today, but, my exam is tomorrow so I need to save time as much as possible, so, it was easier, faster to attach it as image .. I know the easiest way is not always the right one ...
Yes 2, I posted it in the wrong forum, but again, I'm soooo hurried on this, that I didn't notice it ... Am I excused?
and thanks for your quick answer, actually, now that I see it, it was easy, but I didn't see it on the CAT ... so, not confident for tomorrow, even if I dont want a 800 !! ...
Thanks again Stuart for helping people u don't even know !
Silvia