BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem
TTP OnDemand GMAT Video Course
Featured Course

Target Test Prep GMAT OnDemand

Scott Woodbury-Stewart’s private virtual classroom — 400 hours of master-class video lessons for the GMAT Focus Edition.

  • 715+ score guarantee — highest in the industry (99th percentile)
  • 52 chapters · 1,500+ lessons · 4,000+ practice questions
  • 400 hours of video · 1,500+ instructor-led HD smartboard lessons
  • 300,000+ students accepted to Harvard, Stanford, Wharton, Booth & Sloan & more
  • 24/7 live support + weekly Zoom office hours with GMAT instructors
  • TTP AI Assist — 24/7 AI-powered virtual tutor for instant help
  • 1,200+ flashcards + AI-powered study assistant & daily calendar
  • OnDemand, LiveTeach & GMAT Bootcamp formats available
  • Also: GRE, SAT Math & Executive Assessment courses
  • MBA Admissions Consulting now available
  • 🏆 2025 EdTech Breakthrough Award: Test Prep Solution Provider of the Year
  • 200,000+ students served
  • 5-day free trial — $0 to start, no auto-billing, cancel anytime
★★★★★ 5.0 (559 reviews)
130-pt guarantee
$0 to start then $127/mo
Start Free 5-Day Trial Read 559 Reviews →

If \(P\) is the product of all the positive multiples of 11

Expert replies
Post new topic Post Reply
Previous Topic Next Topic
Legendary Member
Posts: 2548
Joined: Sun Oct 29, 2017 2:04 pmFollowed by: 6 members
by swerve » Sat Aug 03, 2019 10:46 am

Timer

00:00

Answers

A

B

C

D

E

Stats

Difficulty—

If \(P\) is the product of all the positive multiples of 11 less than 100, then what is the sum of the distinct primes of \(P\)?

A. 22
B. 28
C. 45
D. 49
E. 89

The OA is B

Source: Magoosh
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Source: — Problem Solving |

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 2623
Joined: Mon Jun 02, 2008 3:17 amFollowed by: 355 members
Location: Montreal
Thanked: 1090 times
GMAT Score:780

by Ian Stewart » Sun Aug 04, 2019 5:07 am
"the distinct primes of P" doesn't mean anything in math, if P is a number. I'm not sure if the question has been correctly transcribed, but they surely mean to say "the distinct prime divisors of P".

The product of the positive multiples of 11 less than 100 is:

(11)(22)(33) ... (99) = (1)(11)(2)(11)(3)(11) ... (9)(11) = 11^9 * 9!

and since 9! is divisible by the primes less than or equal to 9, so by 2, 3, 5, and 7, this product is divisible by the primes 2, 3, 5, 7 and 11, which sum to 28.
For online GMAT math tutoring, or to buy my higher-level Quant books and problem sets, contact me at ianstewartgmat at gmail.com

ianstewartgmat.com
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 8157
Joined: Sat Apr 25, 2015 10:56 amFollowed by: 29 members
Location: Los Angeles, CA
Thanked: 43 times

by Scott@TargetTestPrep » Sun Aug 11, 2019 6:15 pm
swerve wrote:If \(P\) is the product of all the positive multiples of 11 less than 100, then what is the sum of the distinct primes of \(P\)?

A. 22
B. 28
C. 45
D. 49
E. 89

The OA is B

Source: Magoosh
We can create the following expression:

11 x 2(11) x 3(11) x 4(11) x 5(11) x 6(11) x 7(11) x 8(11) x 9(11)

We see that the prime factors of P are 2, 3, 5, 7, and 11. So, the sum of those distinct primes is 2 + 3 + 5 + 7 + 11 = 28.

Answer: B

Scott Woodbury-Stewart
Founder and CEO
[email protected]

Image

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

ImageImage
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Post new topic Post Reply
• Page 1 of 1