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 350,000 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: gmat prep question [#permalink]
27 May 2009, 15:19

I guess the first step would be to replace the fractions with their reciprocals, which you can do if you do the entire equation, so

(1/4)^M * (1/5)^18 = 10^35 * 2

4^M * 5^18 = 10^35 * 2

you then turn both sides into factors, 10 into 5s and 2s, and you get (parenthesis means amount of that number in the multiple, sth like 5*5*5*5*5*5 = 5(6))

4 (M) * 5 (18) = 5 (35) * 2 (36)

divide by the eighteen fives

4(M) = 5(17) * 2(36)

we can say that 4(18) = 2(36), so we know that M>18, eliminate A and B

by taking these out of the equation we say the solution is N+18

4(N) = 5(17)

if you subtract 18 from C,D,and E they are 16, 17. and 18

it actually doesn't equal out to any of them..imagine that. I would answer E tho, because it is def. larger than 17.

yeah IDK maybe someone sees my mistake... is this a reliable question? bc I have seen errors in Kaplan and other test providers. I actually entered all of the possible answers into the original equation in a calculator and couldn't get them to equal so I am pretty sure the question is flawed.

Re: gmat prep question [#permalink]
27 May 2009, 17:00

could you make sure you wrote it down right? I have never seen a GMATPREP question flawed, but if you plug 35 into that formula with a calculator it does not work. i would check your software again. Or maybe a parenthesis or sth...

There are some questions that are discussed frequently and it is one of them. I believe it tests a basic concept of power. Do you guys also think that it is really difficult or is just a coincident ?

Administrator, can we short the questions according to the response or frequency of posting? _________________

Re: gmat prep question [#permalink]
28 May 2009, 13:24

Yeah this question is def pretty straightforward. I guess it tests your understanding of reciprocals, powers, etc. If it was early in the test it isn't supposed to be one of the more difficult ones.

Re: gmat prep question [#permalink]
25 Oct 2010, 11:23

Question: isn't it 'dangerous' to just convert to their reciprocals without considering what's in the numerator... ?What's the reasoning to convert to reciprocals (apart from that it is easier to work with after conversion) ?

Re: gmat prep question [#permalink]
25 Oct 2010, 12:35

Expert's post

n2739178 wrote:

Question: isn't it 'dangerous' to just convert to their reciprocals without considering what's in the numerator... ?What's the reasoning to convert to reciprocals (apart from that it is easier to work with after conversion) ?

n2739178: The reasoning behind converting to reciprocals is the oft used 'cross multiplication' If I have (\frac{1}{2})^3 = (\frac{1}{2})^m and I need to find the value of m, I can simply treat this as \frac{1}{2^3} = \frac{1}{2^m} and cross multiply to get 1.2^m = 1.2^3. So the left side denominator goes to right with the right side numerator and right side denominator goes to left with the left side numerator. Here, since the numerators are 1, it doesn't matter.

Though, if you have all the 2s of the left side and the right side in the denominator, you can simply compare them there and do not need to cross multiply. Here I can simply say m =3. The important thing is that all powers of a certain prime should be consolidated in one place on the left side and same for the right side.

e.g. 3^5.(\frac{1}{2.3})^3 = (\frac{1}{2})^m.3^n

\frac{3^{2}}{2^3} = (\frac{1}{2^m}).3^n Here m = 3 and n = 2 _________________

Re: gmat prep question [#permalink]
25 Oct 2010, 13:19

actually, is there a reason not to apply the exponent rule where for example (\frac{1}{2})exponent m = 1 exponent m / m2 exponent m ? (sorry I can't get the superscript to work...)

I'm getting confused because the rule states you have to do that... But I noticed you didn't give 1 the power of m for example...

Re: gmat prep question [#permalink]
25 Oct 2010, 16:49

Expert's post

n2739178 wrote:

actually, is there a reason not to apply the exponent rule where for example (\frac{1}{2})exponent m = 1 exponent m / m2 exponent m ? (sorry I can't get the superscript to work...)

I'm getting confused because the rule states you have to do that... But I noticed you didn't give 1 the power of m for example...

I am sorry, I didn't get your question. Once you type using fraction or powers, highlight the entire Math part and click 'm' given above. It lets the editor know that Math symbols are used here.

Anyway, if your confusion is that why did I not give 1 the power of m, it is only because no matter what m is, 1 will remain 1. 1 to any power is still 1. Rather than 1, if the numerator was 2, I would have definitely written it as 2^m. The exponent has to be applied to both numerator and denominator in such a case. If your question is something else, let me know. _________________

I´ve done an interview at Accepted.com quite a while ago and if any of you are interested, here is the link . I´m through my preparation of my second...

It has been a good week so far. After the disappointment with my GMAT score, I have started to study again, re-schedule the new test date and talked with...

It’s here. Internship season. The key is on searching and applying for the jobs that you feel confident working on, not doing something out of pressure. Rotman has...