Data Sufficiency

HI abhasjha,

In certain DS questions, the answer to the question is hidden behind some "math fat." By doing some basic algebra, the exact answer to the question can be found "hidden" in a given Fact.

Here, we're asked if Y < 2X. This is a YES/NO question.

Fact 1: Y/4 < X/2

Here, we can multiply both sides by 4....

Y < 2X

Now we KNOW that Y < 2X, so the answer to the question is ALWAYS YES.
Fact 1 is SUFFICIENT

Fact 2: (Y-2X)/3 < 0

Again, a bit of algebra will simplify this inequality....multiply both sides by 3

Y - 2X < 0

Y < 2X

Here, we also KNOW that Y < 2X, so the answer to the question is ALWAYS YES.
Fact 2 is SUFFICIENT

Final Answer: D

GMAT assassins aren't born, they're made,
Rich

abhasjha wrote:Is y < 2x?

(1) y/4 < x/2

(2)(y - 2x)/3 < 0

Target question: Is y < 2x? (YES/NO question)

Statement 1: y/4 < x/2
Eliminate the fractions by multiplying both sides by 4 to get: y < 2x
PERFECT! This matches the question our target question is asking.
So, YES, it is definitely the case that y < 2x
Since we can answer the target question with certainty, statement 1 is SUFFICIENT

Statement 2: (y - 2x)/3 < 0
To analyze this statement, we can use something I call The Something Method (free video here: https://www.gmatprepnow.com/module/gmat- ... ing?id=988)
So, this statement tell us that (something)/3 < 0
3 is a positive #, so we have: (something)/(positive #) < 0
This tells us that something is NEGATIVE
So, something < 0
This means y - 2x < 0
Add 2x to both sides to get y < 2x
PERFECT! This matches the question our target question is asking.
So, YES, it is definitely the case that y < 2x
Since we can answer the target question with certainty, statement 2 is SUFFICIENT

Answer = D

Cheers,
Brent