BengalScientist wrote:

Is p + q > 1/p + 1/q?

(1) p < q < 1

(2) pq < 1

Target question: Is p + q > 1/p + 1/q ?This is a good candidate for

rephrasing the target question.

Aside: Here’s a video with tips on rephrasing the target question: http://www.gmatprepnow.com/module/gmat-data-sufficiency?id=1100Let's rewrite 1/p + 1/q

Find a common denominator of pq to get: q/pq + p/pq

Add to get: (p + q)/pq

REPHRASED target question: Is p + q > (p + q)/pq?Notice that (p + q) appears on both sides of the inequality.

Also notice that if pq = 1, the two quantities, (p+q) and (p + q)/pq, will be equal.

Also notice that if p+q is positive AND pq is between 0 and 1, then (p+q) < (p + q)/pq

Also notice that if p+q is negative AND pq is between 0 and 1, then (p+q) > (p + q)/pq

These observations will help up TEST VALUES

Statement 1: p < q < 1 There are several values of p and q that satisfy statement 1. Here are two:

Case a: p = 1/4 and q = 1/2. In which case, p + q = 1/4 + 1/2 =

3/4, AND (p + q)/pq = (3/4)/(1/8) =

6. In other words,

(p+q) < (p + q)/pqCase b: p = -1/2 and q = -1/4. In which case, p + q = (-1/2) + (-1/4) =

-3/4, AND (p + q)/pq = (-3/4)/(1/8) =

-6. In other words,

(p+q) > (p + q)/pqSince we cannot answer the

REPHRASED target question with certainty, statement 1 is NOT SUFFICIENT

Statement 2: pq < 1 There are several values of p and q that satisfy statement 2. Here are two:

Case a: p = 1/4 and q = 1/2. In which case, p + q = 1/4 + 1/2 =

3/4, AND (p + q)/pq = (3/4)/(1/8) =

6. In other words,

(p+q) < (p + q)/pqCase b: p = -1/2 and q = -1/4. In which case, p + q = (-1/2) + (-1/4) =

-3/4, AND (p + q)/pq = (-3/4)/(1/8) =

-6. In other words,

(p+q) > (p + q)/pqSince we cannot answer the

REPHRASED target question with certainty, statement 2 is NOT SUFFICIENT

Statements 1 and 2 combined Notice that I used the SAME values for p and q in my earlier work. So, the same values satisfy BOTH statements. That is....

There are several values of p and q that satisfy BOTH statements. Here are two:

Case a: p = 1/4 and q = 1/2. In which case, p + q = 1/4 + 1/2 =

3/4, AND (p + q)/pq = (3/4)/(1/8) =

6. In other words,

(p+q) < (p + q)/pqCase b: p = -1/2 and q = -1/4. In which case, p + q = (-1/2) + (-1/4) =

-3/4, AND (p + q)/pq = (-3/4)/(1/8) =

-6. In other words,

(p+q) > (p + q)/pqSince we cannot answer the

REPHRASED target question with certainty, the combined statements are NOT SUFFICIENT

Answer: E

Cheers,

Brent

_________________

Brent Hanneson – GMATPrepNow.com

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