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: The integers a, b, and c are positive a/b = 5/2, and a/c [#permalink]
25 Feb 2012, 23:30

1

This post received KUDOS

Expert's post

1

This post was BOOKMARKED

Chembeti wrote:

The integers a, b, and c are positive, a/b = 5/2, and a/c = 7/5. What is the smallest possible value of 2a + b?

A. 63 B. 70 C. 84 D. 95 E. 105

Since \(\frac {a}{b}=\frac {5}{2}\), and \(\frac {a}{c}=\frac {7}{5}\) then \(a\) must be a multiple of both 5 and 7, so the lowest value of \(a\) is \(5*7=35\) (note that \(a\) is a positive integer). Then the lowest value of \(b\) would be \(2*7=14\), as \(\frac {a}{b}=\frac {5}{2}=\frac {5*7}{2*7}=\frac {35}{14}\), so the lowest value of \(2a+b=2*35+14=84\).

Answer: C.

Or: since \(\frac {a}{b}=\frac {5}{2}\) then \(a=\frac{5b}{2}\) and \(2a + b=2*\frac{5b}{2}+b=6b\), so it's a multiple of 6. The only multiple of 6 among the answer choices is 84 (C).

Re: The integers a, b, and c are positive a/b = 5/2, and a/c [#permalink]
04 Feb 2013, 07:15

why is the value of '2' for b have '7' multiplying to it , 7 is the the value for the fraction a/c . I understand how you are getting the lowest value for 'a' but not for 'b' .

Re: The integers a, b, and c are positive a/b = 5/2, and a/c [#permalink]
04 Feb 2013, 07:23

Expert's post

pharm wrote:

why is the value of '2' for b have '7' multiplying to it , 7 is the the value for the fraction a/c . I understand how you are getting the lowest value for 'a' but not for 'b' .

Thanks

The lowest value of a is 35. Now, if a=35, then from a/b = 5/2 we'll have that b=14.

Re: The integers a, b, and c are positive a/b = 5/2, and a/c [#permalink]
04 Feb 2013, 07:58

Bunuel wrote:

pharm wrote:

why is the value of '2' for b have '7' multiplying to it , 7 is the the value for the fraction a/c . I understand how you are getting the lowest value for 'a' but not for 'b' .

Thanks

The lowest value of a is 35. Now, if a=35, then from a/b = 5/2 we'll have that b=14.

Hope it's clear.

you said that from a/b = 5/2 , b=14 . Since in a/b , 'b' was = 2 . the common number is '7' that is being multipled to 5 and 2 in order to reach the lowest possible values correct? so to get " b's " lowest possible value you multiplied = '2 * 7= 14' . Does '7' hold any significance that it was used for the values in 'a' & 'b' to reach there lowest possible values ?

Re: The integers a, b, and c are positive a/b = 5/2, and a/c [#permalink]
16 Feb 2013, 14:57

It is mentioned that a/c=7/5. So from this ratio we know that 7 needs to be a factor of a. From a/b=5/2 we again know that a must contain 5. Hence, the minimum value of a must be 35.

Using the ratio a/b=5/2, we know that b must have 2 and must also contain 7 as a also contained 7 which was cancelled while calculating he simplest form of ratio.

pharm wrote:

Bunuel wrote:

pharm wrote:

why is the value of '2' for b have '7' multiplying to it , 7 is the the value for the fraction a/c . I understand how you are getting the lowest value for 'a' but not for 'b' .

Thanks

The lowest value of a is 35. Now, if a=35, then from a/b = 5/2 we'll have that b=14.

Hope it's clear.

you said that from a/b = 5/2 , b=14 . Since in a/b , 'b' was = 2 . the common number is '7' that is being multipled to 5 and 2 in order to reach the lowest possible values correct? so to get " b's " lowest possible value you multiplied = '2 * 7= 14' . Does '7' hold any significance that it was used for the values in 'a' & 'b' to reach there lowest possible values ?

Re: The integers a, b, and c are positive a/b = 5/2, and a/c [#permalink]
09 Apr 2014, 09:34

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. _________________

Type of Visa: You will be applying for a Non-Immigrant F-1 (Student) US Visa. Applying for a Visa: Create an account on: https://cgifederal.secure.force.com/?language=Englishcountry=India Complete...