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:
Re: Anything Wrong in this problem??? Can anyone dare to solve? [#permalink]
08 Aug 2010, 03:10
5
This post received KUDOS
Expert's post
5
This post was BOOKMARKED
amitjash wrote:
If 3^6x = 8,100, what is the value of (3^x – 1)^3 ?
A. 90 B. 30 C. 10 D. 10/3 E. 10/9
Please when posting such questions make sure that it's not ambiguous.
Correct question is: If 3^(6x) = 8,100, what is the value of [3^(x-1)]^3? Or it can be written using the formating as: If \(3^{6x}=8,100\), what is the value of \((3^{x-1})^3\)? (It's not hard at all).
Re: Anything Wrong in this problem??? Can anyone dare to solve? [#permalink]
08 Aug 2010, 07:18
Excellent. No a side note, Bunuel, I started approaching this using the "power of prime in a number" - I had seen the link somewhere which had the formula N/p + N/p^2+N/p^3... until N>p^x and thought of equating that to 6x and solve thus. I know yours is much simpler. However would that approach have worked? Is that formula exactly saying what is the highest power of the prime in the number? _________________
Re: Anything Wrong in this problem??? Can anyone dare to solve? [#permalink]
08 Aug 2010, 07:41
1
This post received KUDOS
Expert's post
mainhoon wrote:
Excellent. No a side note, Bunuel, I started approaching this using the "power of prime in a number" - I had seen the link somewhere which had the formula N/p + N/p^2+N/p^3... until N>p^x and thought of equating that to 6x and solve thus. I know yours is much simpler. However would that approach have worked? Is that formula exactly saying what is the highest power of the prime in the number?
No need to complicate simple questions.
The formula is correct (everything-about-factorials-on-the-gmat-85592.html) but it has nothing to do with this problem, (highest power of 3 in 81,000 won't be equal to 6x, because 3^(6x)=81,000=2^m*3^n*5^k, so as 81,000 has other factors than 3 in it then 6x won't be an integer at all). _________________
Re: Anything Wrong in this problem??? Can anyone dare to solve? [#permalink]
08 Aug 2010, 07:56
When I think some more, I don't think we can use that formula. Isn't that formula for factorials - (a) N! not N and (b) as you rightly pointed out it would result in a fraction for 6x, not integer.
For 3^(3x) = 90, if I wanted to solve it, it is clear than x is fractional. So is the answer basically taking logarithms? Any other way? _________________
Q11: If 3^6x = 8,100, what is the value of 3^((x – 1)3) ? 3 A. 90 B. 30 C. 10 D. 10/3 E. 10/9
In a question such as this where you have \(3^{6x} = 8100\) where 8100 is not a perfect sixth power but the options do not have irrational numbers, you should immediately go and analyze what is asked. You will not need to solve for x. You will end up using either \(3^{6x} = 8100\) or \(3^{3x} = 90\) _________________
Re: Anything Wrong in this problem??? Can anyone dare to solve? [#permalink]
01 Jun 2013, 19:09
Bunuel wrote:
amitjash wrote:
If 3^6x = 8,100, what is the value of (3^x – 1)^3 ?
A. 90 B. 30 C. 10 D. 10/3 E. 10/9
Please when posting such questions make sure that it's not ambiguous.
Correct question is: If 3^(6x) = 8,100, what is the value of [3^(x-1)]^3? Or it can be written using the formating as: If \(3^{6x}=8,100\), what is the value of \((3^{x-1})^3\)? (It's not hard at all).
Re: Anything Wrong in this problem??? Can anyone dare to solve? [#permalink]
02 Jun 2013, 03:13
Expert's post
cumulonimbus wrote:
Bunuel wrote:
amitjash wrote:
If 3^6x = 8,100, what is the value of (3^x – 1)^3 ?
A. 90 B. 30 C. 10 D. 10/3 E. 10/9
Please when posting such questions make sure that it's not ambiguous.
Correct question is: If 3^(6x) = 8,100, what is the value of [3^(x-1)]^3? Or it can be written using the formating as: If \(3^{6x}=8,100\), what is the value of \((3^{x-1})^3\)? (It's not hard at all).
Re: If 3^(6x) = 8,100, what is the value of [3^(x-1)]^3? [#permalink]
22 Jun 2015, 23:45
Hello from the GMAT Club BumpBot!
Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).
Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email. _________________
As I’m halfway through my second year now, graduation is now rapidly approaching. I’ve neglected this blog in the last year, mainly because I felt I didn’...
Perhaps known best for its men’s basketball team – winners of five national championships, including last year’s – Duke University is also home to an elite full-time MBA...
Hilary Term has only started and we can feel the heat already. The two weeks have been packed with activities and submissions, giving a peek into what will follow...