• Veritas Prep
    Free Veritas GMAT Class
    Experience Lesson 1 Live Free

    Available with Beat the GMAT members only code

    MORE DETAILS
    Veritas Prep
  • 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
  • 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
  • EMPOWERgmat Slider
    1 Hour Free
    BEAT THE GMAT EXCLUSIVE

    Available with Beat the GMAT members only code

    MORE DETAILS
    EMPOWERgmat Slider
  • Magoosh
    Magoosh
    Study with Magoosh GMAT prep

    Available with Beat the GMAT members only code

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

    Available with Beat the GMAT members only code

    MORE DETAILS
    PrepScholar GMAT
  • 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
  • Economist Test Prep
    Free Trial & Practice Exam
    BEAT THE GMAT EXCLUSIVE

    Available with Beat the GMAT members only code

    MORE DETAILS
    Economist Test Prep

OG If n is the product

This topic has 5 expert replies and 0 member replies
AbeNeedsAnswers Master | Next Rank: 500 Posts Default Avatar
Joined
02 Jul 2017
Posted:
191 messages
Followed by:
1 members
Thanked:
1 times

OG If n is the product

Post Tue Jul 25, 2017 8:16 pm
Elapsed Time: 00:00
  • Lap #[LAPCOUNT] ([LAPTIME])
    If n is the product of the integers from 1 to 8, inclusive, how many different prime factors greater than 1 does n have?

    A) Four
    B) Five
    C) Six
    D) Seven
    E) Eight

    A

    Need free GMAT or MBA advice from an expert? Register for Beat The GMAT now and post your question in these forums!
    Post Tue Jul 25, 2017 8:52 pm
    AbeNeedsAnswers wrote:
    If n is the product of the integers from 1 to 8, inclusive, how many different prime factors greater than 1 does n have?

    A) Four
    B) Five
    C) Six
    D) Seven
    E) Eight

    A
    We have n = 1*2*3*4*5*6*7*8 = 8!

    Thus, the different prime factors greater than 1 are; 2, 3, 5, and 7: Four

    The correct answer: A

    Hope this helps!

    Download free ebook: Manhattan Review GMAT Quantitative Question Bank Guide

    -Jay
    _________________
    Manhattan Review GMAT Prep

    Locations: New York | Singapore | Doha | Lausanne | and many more...

    Schedule your free consultation with an experienced GMAT Prep Advisor! Click here.

    Post Wed Jul 26, 2017 6:15 am
    AbeNeedsAnswers wrote:
    If n is the product of the integers from 1 to 8, inclusive, how many different prime factors greater than 1 does n have?

    A) Four
    B) Five
    C) Six
    D) Seven
    E) Eight

    A
    n = (1)(2)(3)(4)(5)(6)(7)(8)
    = (1)(2)(3)(2)(2)(5)(2)(3)(7)(2)(2)(2)
    The prime factors are 2, 3, 5 and 7

    Answer: A

    _________________
    Brent Hanneson – Founder of GMATPrepNow.com
    Use our video course along with Beat The GMAT's free 60-Day Study Guide

    Check out the online reviews of our course
    Come see all of our free resources

    GMAT Prep Now's comprehensive video course can be used in conjunction with Beat The GMAT’s FREE 60-Day Study Guide and reach your target score in 2 months!
    Post Wed Jul 26, 2017 6:52 pm
    Hi AbeNeedsAnswers,

    With these types of Prime Factorization questions, it often helps to 'break down' the math into 'pieces' (since the individual pieces are rarely all that difficult to deal with.

    Here, we're asked for the number of different prime factors in the product of 1 to 8, inclusive (essentially 8!). That product would include the following factors:
    1
    2
    3
    4 = (2)(2)
    5
    6 = (2)(3)
    7
    8 = (2)(2)(2)

    Thus, the different primes are: 2, 3, 5 and 7... and there are 4 of them.

    Final Answer: A

    GMAT assassins aren't born, they're made,
    Rich

    _________________
    Contact Rich at Rich.C@empowergmat.com

    GMAT/MBA Expert

    Post Mon Aug 14, 2017 11:52 am
    AbeNeedsAnswers wrote:
    If n is the product of the integers from 1 to 8, inclusive, how many different prime factors greater than 1 does n have?

    A) Four
    B) Five
    C) Six
    D) Seven
    E) Eight

    A
    n = 8 x 7 x 6 x 5 x 4 x 3 x 2 x 1

    We can prime factorize and we have:

    n = 2^7 x 3^2 x 5^1 x 7^1

    Thus, n has 4 different prime factors.

    Alternate solution:

    In general, the number of distinct prime factors that k! (where k > 1) has is the number of prime numbers less than or equal to k. We have n = 8!, so k = 8; the number of prime numbers less than or equal to 8 is 4, namely, 2, 3, 5, and 7.

    Answer: A

    _________________

    Scott Woodbury Stewart Founder & CEO
    GMAT Quant Self-Study Course - 500+ lessons 3000+ practice problems 800+ HD solutions
    5-Day Free Trial 5-DAY FREE, FULL-ACCESS TRIAL TTP QUANT

    GMAT/MBA Expert

    Post Fri Aug 18, 2017 2:15 pm
    Count the unique primes in 2 * 3 * 4 * 5 * 6 * 7 * 8

    Enroll in a Veritas Prep GMAT class completely for FREE. Wondering if a GMAT course is right for you? Attend the first class session of an actual GMAT course, either in-person or live online, and see for yourself why so many students choose to work with Veritas Prep. Find a class now!

    Best Conversation Starters

    1 Vincen 152 topics
    2 lheiannie07 61 topics
    3 Roland2rule 49 topics
    4 ardz24 40 topics
    5 LUANDATO 32 topics
    See More Top Beat The GMAT Members...

    Most Active Experts

    1 image description Brent@GMATPrepNow

    GMAT Prep Now Teacher

    141 posts
    2 image description EconomistGMATTutor

    The Economist GMAT Tutor

    107 posts
    3 image description GMATGuruNY

    The Princeton Review Teacher

    106 posts
    4 image description Rich.C@EMPOWERgma...

    EMPOWERgmat

    104 posts
    5 image description Matt@VeritasPrep

    Veritas Prep

    76 posts
    See More Top Beat The GMAT Experts