Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized for You

we will pick new questions that match your level based on your Timer History

Track Your Progress

every week, we’ll send you an estimated GMAT score based on your performance

Practice Pays

we will pick new questions that match your level based on your Timer History

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

It appears that you are browsing the GMAT Club forum unregistered!

Signing up is free, quick, and confidential.
Join other 500,000 members and get the full benefits of GMAT Club

Registration gives you:

Tests

Take 11 tests and quizzes from GMAT Club and leading GMAT prep companies such as Manhattan GMAT,
Knewton, and others. All are free for GMAT Club members.

Applicant Stats

View detailed applicant stats such as GPA, GMAT score, work experience, location, application
status, and more

Books/Downloads

Download thousands of study notes,
question collections, GMAT Club’s
Grammar and Math books.
All are free!

Thank you for using the timer!
We noticed you are actually not timing your practice. Click the START button first next time you use the timer.
There are many benefits to timing your practice, including:

Hey ! Unfortunately, I still don't get where that '3' comes from... Just don't see it... Could anyone explain further in more detail?! Would be great! _________________

Re: If 2^x-2^(x-2)=3*2^13 what is the value of x? [#permalink]

Show Tags

23 Jul 2013, 11:51

Bunuel wrote:

Step by step:

\(2^x(1-\frac{1}{2^{2}})=3*2^{13}\)

\(2^x(\frac{2^2-1}{2^{2}})=3*2^{13}\)

Hey, now its clear where the 3 comes from but how did u get the 2^2 there? Sry, was a long day... I bet its easy as hell but I'm just confused atm.. _________________

Re: If 2^x-2^(x-2)=3*2^13 what is the value of x? [#permalink]

Show Tags

23 Jul 2013, 12:41

Hey, that I understand... but how did u get the 2^2 onto the fraction again to get 2^2-1/2^2 ? I must miss something very fundamental indeed.. _________________

Re: If 2^x-2^(x-2)=3*2^13 what is the value of x? [#permalink]

Show Tags

06 Oct 2013, 14:11

Hello Everyone,

While completing the GMAT prep exam I stumbled upon a problem solving question that am not able to crack and I am seeking for some advice/pointers on this question:

If 2^x - 2^x-2 = 3(2^13) what is x?

It would be easier to solve if the 3 was not included in the equation at all but of course nothing about the gmat is easy.

Am not looking for the answer just pointers. I did review the exponent rules from the MGMAT Number Properties guide but according to the rule for a * b^ This kind of expression can not be simplified any further so it's kind of confusing,

Re: If 2^x-2^(x-2)=3*2^13 what is the value of x? [#permalink]

Show Tags

06 Oct 2013, 14:14

Expert's post

dilevbare1 wrote:

Hello Everyone,

While completing the GMAT prep exam I stumbled upon a problem solving question that am not able to crack and I am seeking for some advice/pointers on this question:

If 2^x - 2^x-2 = 3(2^13) what is x?

It would be easier to solve if the 3 was not included in the equation at all but of course nothing about the gmat is easy.

Am not looking for the answer just pointers. I did review the exponent rules from the MGMAT Number Properties guide but according to the rule for a * b^ This kind of expression can not be simplified any further so it's kind of confusing,

Thanks for your help in advance

Merging similar topics. Please refer to the solutions above.

Re: If 2^x-2^(x-2)=3*2^13 what is the value of x? [#permalink]

Show Tags

26 Feb 2014, 20:31

4

This post received KUDOS

1

This post was BOOKMARKED

One more method:

\(2^x - 2^{(x-2)} = 3 * 2^{13}\)

\(2^x - 2^{(x-2)} = ( 4-1 ) * 2^{13}\)

\(2^x - 2^{(x-2)} = 4 * 2^{13} - 1 * 2^{13}\)

\(2^x - 2^{(x-2)} = 2^{15} - 2^{13}\)

Comparing both sides, we get x = 15 = Answer = D

What I like about this method is we need not have to expand/solve the LHS of the equation. Just adjust 3 of the RHS as (4-1) & it does the trick _________________

Kindly press "+1 Kudos" to appreciate

Last edited by PareshGmat on 27 Oct 2014, 21:30, edited 2 times in total.

So, my final tally is in. I applied to three b schools in total this season: INSEAD – admitted MIT Sloan – admitted Wharton – waitlisted and dinged No...

A few weeks ago, the following tweet popped up in my timeline. thanks @Uber_Mumbai for showing me what #daylightrobbery means!I know I have a choice not to use it...

“This elective will be most relevant to learn innovative methodologies in digital marketing in a place which is the origin for major marketing companies.” This was the crux...