Session 4: GMAT 4 Quant: Algebra 1 - Q7

[AlexS613]

Hi,

I do not understand the solution to this question. From statement 1, alone, and statement 2, alone, I am able to determine that x=12 and y=3. The simplified question is asking is x+y=15. If I am able to determine x and y for statement 1, alone, and statement 2, alone, then shouldn't the correct answer be D (most statements alone are sufficient? In the explanation for the why answer C is correct, the instructor points out that by combining you can solve for values of x and y and find an answer...but I can do this with each statement alone? Please help!

[RonPurewal]

hi,
welcome to the forum -- but please familiarize yourself with the forum rules before posting.

any problem posted here must be reproduced in its entirety, exactly as originally provided.
if there are answer choices, we need all those, too -- as well as the choice that's indicated as officially correct.

and for problems in THIS folder, we also need a citation of the original source (that's the ORIGINAL source -- whoever owns the copyright).

__

[RonPurewal]

also --
most of the problems we use in our course are from the OG. if this is an OG problem, then, unfortunately, we can't discuss it here (per GMAC's express request).
...but, if you're enrolled in a course, you could e-mail your instructor directly with (occasional) questions like this.

if this problem is NOT from OG, please post it
• ...in the appropriate folder,
• ...in accordance with the forum rules (as described above).

thanks.