GMAT prep question - is the OA wrong?

[StarDust845]

The question is simple.

If x > 0, is x > y ?

1) 7x - 4y = 3
2) 4x - 7y = 3

I believe the answer is D, but OA is different. Is my answer wrong?

Calista.

[sujaysolanki]

Corrected to B ...trying picking numbers say put x =1 or 1/2 it will hold for stmt 1 ..not to for Hope this helps

[StarDust845]

Ah ha! I see what you are saying and then I approached my solution again and now I see the fallacy in my reasoning.

Here is how I solved (or thought that I solved) it.

The slope of the first equation is > 1. So I plotted the graph briefly and because slope is > 1, I assumed x is always less than y for x > 0.

For e.g assume a line with slope 1 passing through origin. The points in Quadrant I towards left of that line will always be x <y> y I extrapolated this fundamental to this GMAT question.. I assumed wrong obviously.

This can't be extrapolated. Thanks for your answer. This probably saved me from more mistakes, I would have made down the line.

Calista.

[samirpandeyit62]

If x > 0, is x > y ?

1) 7x - 4y = 3

i.e 7x > 4y or x > 4/7*y

so in this case x>y is possible, but it is also possibe that

x is less than y e.g x =0.8 *y

2) 4x - 7y = 3

i.e 4x > 7y

or x > 7/4*y

i.e x > 7/4*y > y

i.e x >y SUFF B

Hi Eric/Gabriel,
Is there a problem with inequality signs, whenever I put two inequality signs on successive lines, they somehow get merged into one.

[StarDust845]

Beautiful! Thanks.

Calista.

[gabriel]

@ Samir, can u send Eric a PM stating the exact problem. Thanks.

Regards.