Live GMAT classes with Target Test Prep start Nov 21 and Nov 22. First class free.

See classes
Target Test Prep · GMAT

Choose how you want to prepare

Learn live with an expert or move at your own pace. Every option includes the complete TTP study system.

Newsweek Readers’ Choice Awards 2026 winner: Target Test Prep, #1 Test Prep

Target Test Prep was voted #1 Best Test Prep in the 2026 Newsweek Readers’ Choice™ Awards.

★★★★★5.0563 reviews
GMATLiveTeachStarts Nov 22
Josh Braslow, Target Test Prep GMAT expert
LIVE ONLINE CLASSES

Get Ready for GMAT Test Day Faster with Live Online Classes

with Josh Braslow, 20+ years in test prep

Nov 22 · Josh Braslow
Sun · 9:30 AM to 12:30 PM ET
Included
40 hours of live online classes + 6 months of TTP OnDemand
  • Attend the first class for free
  • Every class is recorded, so you never fall behind
View classes & enroll
Limited seats availableTarget Test Prep
EALiveTeachOnDemandStart anytime
EXECUTIVE ASSESSMENT

Target Test Prep EA OnDemand

Self-paced EA prep. Study on your schedule.

EXECUTIVE ASSESSMENT

with

165+ EA score guarantee
$05-day trial no automatic billing
Schedule
Included
40 hours of live online classes plus six months of access to the complete TTP EA OnDemand course.
  • 165+ EA Score Guarantee
  • 4,100+ Quant, Verbal, and Integrated Reasoning practice questions
  • 400+ hours of in-depth video lessons
  • 3,000+ step-by-step video solutions
View EA class & enroll Start free 5-day trial
Limited cohort · enrollment openTrial includes full course accessTarget Test Prep
GMATOnDemandStart anytime
SELF-PACED MASTERCLASS

Target Test Prep GMAT OnDemand

Complete access from day one. Study on your schedule.

715+ score guarantee
$0to start then $127/mo
  • Personalized study plan and analytics
  • Thousands of lessons and practice questions
Start free 5-day trial
Read 563 reviewsTarget Test Prep

Defined functions

Expert replies
Post new topic Post Reply
Subscribe topic
Previous Topic Next Topic
Junior | Next Rank: 30 Posts
Posts: 21
Joined: Fri Aug 06, 2010 1:30 am
by anhe123 » Thu Sep 30, 2010 6:27 am
If A*B is the greatest common factor of A and B, A$B is defined as the least common multiple of A
and B, and (A intersection B) is defined as equal to (A*B) $ (A$B), then what is the value of (12 intersection 15)?

How would you solve this? Are there any tips you have for solvning defined functions?[/list]
Top
Join the discussion
Source: — Problem Solving |
User avatar
Master | Next Rank: 500 Posts
Posts: 324
Joined: Mon Jul 05, 2010 6:44 amFollowed by: 3 members
Location: London
Thanked: 70 times

by kmittal82 » Thu Sep 30, 2010 6:40 am
First you need to expand each of the brackets:

(A*B) = (12*15) = 3 (3 is the greatest common factor of 12 and 15)
(A$B) = (12$15) = 60 (60 is the least common multiple of 12 and 15)

>(A*B) $ (A$B),

= 3 $ 60 = Least common multiple of 3 and 60 = 60
Top
Join the discussion
Junior | Next Rank: 30 Posts
Posts: 21
Joined: Fri Aug 06, 2010 1:30 am

by anhe123 » Thu Sep 30, 2010 6:43 am
kmittal82 wrote:First you need to expand each of the brackets:

(A*B) = (12*15) = 3 (3 is the greatest common factor of 12 and 15)
(A$B) = (12$15) = 60 (60 is the least common multiple of 12 and 15)

>(A*B) $ (A$B),

= 3 $ 60 = Least common multiple of 3 and 60 = 60

But what does the dollar sign ($) mean?
Top
Join the discussion
Community Manager
Posts: 991
Joined: Thu Sep 23, 2010 6:19 amFollowed by: 24 members
Location: Bangalore, India
Thanked: 146 times

by shovan85 » Thu Sep 30, 2010 6:44 am
IMO 60

Break the whole expression.
Solve the bracketed individually.
Merge the answers of bracketed to the single expression.
Top
Join the discussion
User avatar
Master | Next Rank: 500 Posts
Posts: 324
Joined: Mon Jul 05, 2010 6:44 amFollowed by: 3 members
Location: London
Thanked: 70 times

by kmittal82 » Thu Sep 30, 2010 6:52 am
andre.heggli wrote:
kmittal82 wrote:First you need to expand each of the brackets:

(A*B) = (12*15) = 3 (3 is the greatest common factor of 12 and 15)
(A$B) = (12$15) = 60 (60 is the least common multiple of 12 and 15)

>(A*B) $ (A$B),

= 3 $ 60 = Least common multiple of 3 and 60 = 60

But what does the dollar sign ($) mean?
Nothing, its just a symbol to represent a mathematical operation... you can replace it with whatever you like.
Top
Join the discussion