mitzwillrockgmat wrote:If x and y are positive, is 3x > 7y?

(1) x > y + 4

(2) -5x < -14y

I've seen alot of posts regarding this question but all are very confusing as some say answer is B while others D.

The answer provided is D though.

When i did this question in a practice test, i picked B but now knowing the answer, I tried working backwards.

Can anyone shed light on what the correct answer actually is & how to approach this question?


This is what I did:

1) I don't get it !

2) -5x<-14y

so x > -14y/-5

x > 2.8y

so 3x > 8.4y hence, 3x >7y

so stat sufficient

outreach wrote:Q is x>2.3y?

option 1

if y=1 then X>5
this satisfies Q
if y=-1 then x>4 *****value of x & y is positive

this satisfies Q

hence A can be correct

option 2 u have already proved

hence D

mitzwillrockgmat wrote:If x and y are positive, is 3x > 7y?

(1) x > y + 4

(2) -5x < -14y

I've seen alot of posts regarding this question but all are very confusing as some say answer is B while others D.

The answer provided is D though.

When i did this question in a practice test, i picked B but now knowing the answer, I tried working backwards.

Can anyone shed light on what the correct answer actually is & how to approach this question?


This is what I did:

1) I don't get it !

2) -5x<-14y

so x > -14y/-5

x > 2.8y

so 3x > 8.4y hence, 3x >7y

so stat sufficient

mitzwillrockgmat wrote:If x and y are positive, is 3x > 7y?

(1) x > y + 4

(2) -5x < -14y

Stuart Kovinsky wrote:

mitzwillrockgmat wrote:If x and y are positive, is 3x > 7y?

(1) x > y + 4

(2) -5x < -14y

We know that x and y are positive, so we can rephrase the question as:

is x/y > 7/3?

(1) x > y + 4

let's start by picking very small values: y=1 and x=6 (we could pick smaller values if we wanted, since we don't have to pick integers):

Is 6/1 > 7/3? YES

now let's try really big values:

y = 95, x=100

is 100/95 > 7/3? NO

accordingly, (1) is not sufficient alone.