Does 5x + 2y = 12 ?

[fltingley]

(1) x = 2

(2) 10x = 24 – 4y


Can someone please help me understand why the answer is [spoiler]B / (2)? 10x = 24 - 4y can just break down to be 5x + 2y = 12, so how is making an equating with 2 variables equal to the exact equation make it sufficient? [/spoiler]

Thanks in advance!

[iwant700plus]

This is a Yes/No question.

1) X=2, temptation is to plug 2 into the equation, but the question is asking us whether 5x+2y=12. We don't know the value of y, so could be Yes or No depending on value of Y. Insufficient.

2) 10X=24-4Y --> 5x+2y=12. This tells us a definite YES. Sufficient.

Ans. B.

[rs2010]

Where on earth you found this question? :mrgreen:

[fltingley]

Ahhh, yes, the accursed Yes/No DS questions. Thanks for the explanation, iwant700plus. I guess I overlooked that in my quizzing.

To answer your question, hemantsood, I got this question from a Kaplan online quiz. They are randomly assigned, so there's no real number assigned to it. Hope that helps...