[ 3 posts ]

 Print view Previous topic | Next topic

#### Exponents and roots question

Author Message
 Post subject: Exponents and roots question  Posted: Fri Aug 10, 2012 4:12 pm
 Course Students

Posts: 1
 Is 3 to the power of P > 2 to the power of q ?(1) q = 2p(2) q > 0 Can anyone explain this.From my understanding the answer to this question is E. But the explainantion says the correct ans is C.

 Post subject: Re: Exponents and roots question  Posted: Sat Aug 11, 2012 10:53 am
 Course Students

Posts: 15
 There is an explanation for this problem or simply an answer?Experts will explain but here is what I would have done. Is 3^P > 2^QI would start with statement 2. We know Q is positive but this tells us nothing about P. Perhaps P is positive but maybe not. You can easily pick some numbers here to prove this statement is insufficient. If Q were 1 and P were 2, the question would be true. But if Q were 2 and P was 1 the question would be false. INSUFFICIENTStatement 1 tells us that Q = 2PPick some smart numbers to prove insufficiencyQ = 2P1 = 2(1/2) --> Our question above would be FALSE-2 = 2(-1) --> Our question above would be TRUEINSUFFICIENTCombining the statements we know Q is positive (which also implies that P is positive) AND Q = 2PQ = 2P1 = 2(1/2)2 = 2(1)3 = 2(3/2)4 = 2(2)6 = 2(3)Testing each number in to our question up top yields a definitive "NO". Thus, both statements together are sufficient.

 Post subject: Re: Exponents and roots question  Posted: Sun Aug 12, 2012 4:19 am
 ManhattanGMAT Staff

Posts: 8087
 vamsee.sattiraju wrote:Is 3 to the power of P > 2 to the power of q ?(1) q = 2p(2) q > 0 Can anyone explain this.From my understanding the answer to this question is E. But the explainantion says the correct ans is C.hi,from now on, you should actually say what "your understanding of the problem" is; it's hard to respond to your post if we have to mind-read.kyle's approach (testing cases) works.if you have statement 2, you can also substitute q = 2p into the question:Is 3^p > 2^q ?Is 3^p > 2^(2p) ?which is the same as...Is 3^p > (2^2)^p ?Is 3^p > 4^p ?The answer to this question is No if p is non-negative and Yes if p is negative. therefore, if you have the two statements together, it's a definite No. _________________Being well-dressed gives a feeling of inward tranquillity [that] religion is powerless to bestow.C.F. Forbes

Display posts from previous:  Sort by

[ 3 posts ]

#### Who is online

 Users browsing this forum: No registered users and 0 guests

 You cannot post new topics in this forumYou cannot reply to topics in this forumYou cannot edit your posts in this forumYou cannot delete your posts in this forumYou cannot post attachments in this forum

Search for:
 Jump to:  Select a forum ------------------ Ask An Instructor    General GMAT Strategy Questions    GMAT Math       General Math Questions       GMAT Prep Math       Manhattan GMAT CAT Math       Manhattan GMAT Non-CAT Math       Official Guide Math    GMAT Verbal       General Verbal Questions       GMAT Prep Verbal       Manhattan GMAT CAT Verbal       Manhattan GMAT Non-CAT Verbal       Official Guide Verbal    GMAT Integrated Reasoning (IR)       GMAT Prep IR       Manhattan GMAT CAT IR       Manhattan GMAT Non-CAT IR    GMAT AWA Essays Manhattan GMAT    Ask Student Services    Study Groups    GMAT Test Day    Test Centers    Instructor Feedback    Course Feedback B-School    Ask an mbaMission Admissions Consultant    B-School Essays    Business Schools    Professional Networking