• NEW! FREE Beat The GMAT Quizzes
    NEW! FREE Beat The GMAT Quizzes
    NEW! FREE Beat The GMAT Quizzes
    Hundreds of Questions Highly Detailed Reporting Expert Explanations TAKE A FREE GMAT QUIZ
  • 7 CATs FREE!
    If you earn 100 Forum Points

    Engage in the Beat The GMAT forums to earn
    100 points for $49 worth of Veritas practice GMATs FREE

    Veritas Prep
    VERITAS PRACTICE GMAT EXAMS
    Earn 10 Points Per Post
    Earn 10 Points Per Thanks
    Earn 10 Points Per Upvote
    REDEEM NOW

If N is a positive integer...

This topic has 3 expert replies and 1 member reply

If N is a positive integer...

Post
If N is a positive integer and 14N/60 is an integer. What is the smallest value of N for which N has exactly four different prime factors?

A)30
B)60
C)180
D)210
E)cannot be determined

The OA is D.

Why D is the correct answer? Can any expert explain this PS question please?. Thanks.

  • +1 Upvote Post
  • Quote
  • Flag

GMAT/MBA Expert

Post
Hello.

If you see carefully the options on the list you can determine which is the correct answer.

Let's see option by option.

- Option A: 30
30=2*3*5, so 30 has 3 different prime factors. OUT

- Option B: 60
60=2*2*3*5, so 60 has 3 different prime factors. OUT.

- Option C: 180
180=2*2*3*3*5, so 180 has 3 different prime factors, OUT.

- Option D: 210
210=2*3*5*7, so 210 has exactly 4 different prime factors. In addition, 14*210/60=49, so 14N/60 is an integer. CORRECT.

We don't need to analyze the last option.

So, the answer is D.

I hope this answer could help you.

I'm available if youd like any follow up.

_________________
GMAT Prep From The Economist
We offer 70+ point score improvement money back guarantee.
Our average student improves 98 points.

  • +1 Upvote Post
  • Quote
  • Flag
Free 7-Day Test Prep with Economist GMAT Tutor - Receive free access to the top-rated GMAT prep course including a 1-on-1 strategy session, 2 full-length tests, and 5 ask-a-tutor messages. Get started now.

GMAT/MBA Expert

Post
LUANDATO wrote:
If N is a positive integer and 14N/60 is an integer. What is the smallest value of N for which N has exactly four different prime factors?

A)30
B)60
C)180
D)210
E)cannot be determined
14N/60 = 7N/30.

The smallest prime numbers are 2, 3, 5 and 7.
Thus, the smallest integer with 4 different prime factors = 2*3*5*7 = 210.
Test whether N=210 yields an integer value for 7N/30:
(7*210)/30= 7*7 = 49.
Success!
Thus, the least possible value for N = 210.

The correct answer is D.

_________________
Mitch Hunt
Private Tutor for the GMAT and GRE
GMATGuruNY@gmail.com

If you find one of my posts helpful, please take a moment to click on the "UPVOTE" icon.

Available for tutoring in NYC and long-distance.
For more information, please email me at GMATGuruNY@gmail.com.
Student Review #1
Student Review #2
Student Review #3

  • +1 Upvote Post
  • Quote
  • Flag
Free GMAT Practice Test How can you improve your test score if you don't know your baseline score? Take a free online practice exam. Get started on achieving your dream score today! Sign up now.
Post
Hello,

Excellent, your explanations was helpful to me a lot! Thank you so much!

  • +1 Upvote Post
  • Quote
  • Flag
Post
LUANDATO wrote:
If N is a positive integer and 14N/60 is an integer. What is the smallest value of N for which N has exactly four different prime factors?

A)30
B)60
C)180
D)210
E)cannot be determined .
We are given that 14N/60 is an integer, and we need to determine the smallest value of N for which N has exactly four different prime factors.

14N/60 = 7N/30

In order for 7N/30 to be an integer, N must be divisible by 30. In other words, N must be a multiple of 30.

However, since 30 = 2 x 3 x 5, which are 3 different primes, the smallest value of n with 4 different primes is 2 x 3 x 5 x 7 = 210.

Answer: D

_________________

Scott Woodbury-Stewart
Founder and CEO
scott@targettestprep.com



See why Target Test Prep is rated 5 out of 5 stars on BEAT the GMAT. Read our reviews

  • +1 Upvote Post
  • Quote
  • Flag
  • Economist Test Prep
    Free Trial & Practice Exam
    BEAT THE GMAT EXCLUSIVE

    Available with Beat the GMAT members only code

    MORE DETAILS
    Economist Test Prep
  • e-gmat Exclusive Offer
    Get 300+ Practice Questions
    25 Video lessons and 6 Webinars for FREE

    Available with Beat the GMAT members only code

    MORE DETAILS
    e-gmat Exclusive Offer
  • Varsity Tutors
    Award-winning private GMAT tutoring
    Register now and save up to $200

    Available with Beat the GMAT members only code

    MORE DETAILS
    Varsity Tutors
  • EMPOWERgmat Slider
    1 Hour Free
    BEAT THE GMAT EXCLUSIVE

    Available with Beat the GMAT members only code

    MORE DETAILS
    EMPOWERgmat Slider
  • PrepScholar GMAT
    5 Day FREE Trial
    Study Smarter, Not Harder

    Available with Beat the GMAT members only code

    MORE DETAILS
    PrepScholar GMAT
  • The Princeton Review
    FREE GMAT Exam
    Know how you'd score today for $0

    Available with Beat the GMAT members only code

    MORE DETAILS
    The Princeton Review
  • Target Test Prep
    5-Day Free Trial
    5-day free, full-access trial TTP Quant

    Available with Beat the GMAT members only code

    MORE DETAILS
    Target Test Prep
  • Magoosh
    Magoosh
    Study with Magoosh GMAT prep

    Available with Beat the GMAT members only code

    MORE DETAILS
    Magoosh
  • Veritas Prep
    Free Veritas GMAT Class
    Experience Lesson 1 Live Free

    Available with Beat the GMAT members only code

    MORE DETAILS
    Veritas Prep
  • Kaplan Test Prep
    Free Practice Test & Review
    How would you score if you took the GMAT

    Available with Beat the GMAT members only code

    MORE DETAILS
    Kaplan Test Prep

Top First Responders*

1 Ian Stewart 44 first replies
2 Brent@GMATPrepNow 34 first replies
3 Scott@TargetTestPrep 32 first replies
4 Jay@ManhattanReview 31 first replies
5 GMATGuruNY 18 first replies
* Only counts replies to topics started in last 30 days
See More Top Beat The GMAT Members

Most Active Experts

1 image description Scott@TargetTestPrep

Target Test Prep

139 posts
2 image description Max@Math Revolution

Math Revolution

90 posts
3 image description Ian Stewart

GMATiX Teacher

53 posts
4 image description Brent@GMATPrepNow

GMAT Prep Now Teacher

51 posts
5 image description Jay@ManhattanReview

Manhattan Review

31 posts
See More Top Beat The GMAT Experts