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 →

Is 3 a factor of x?

Expert replies
Post new topic Post Reply
Previous Topic Next Topic
User avatar
Elite Legendary Member
Posts: 3991
Joined: Fri Jul 24, 2015 2:28 amFollowed by: 37 members
Location: Las Vegas, USA
Thanked: 19 times
by Max@Math Revolution » Thu Jan 31, 2019 12:57 am

Timer

00:00

Answers

A

B

C

D

E

Stats

Difficulty—

[GMAT math practice question]

Is 3 a factor of x?

1) x-3 is divisible by 6
2) x+3 is divisible by 6
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Source: — Data Sufficiency |
User avatar
GMAT Instructor
Posts: 1449
Joined: Sat Oct 09, 2010 2:16 pmFollowed by: 33 members
Thanked: 59 times

Is 3 a factor of x?

by fskilnik@GMATH » Thu Jan 31, 2019 4:14 am
Max@Math Revolution wrote:[GMAT math practice question]

Is 3 a factor of x?

1) x-3 is divisible by 6
2) x+3 is divisible by 6
$${x \over 3}\,\,\mathop = \limits^? \,\,{\mathop{\rm int}} \,\,\,\,\left( {{\rm{and}}\,\,x\mathop = \limits^? {\mathop{\rm int}} } \right)$$

$$\left( 1 \right)\,\,{{x - 3} \over 6} = {\mathop{\rm int}} \,\,\,\,\mathop \Rightarrow \limits^{ \cdot \,2} \,\,\,\,{{x - 3} \over 3} = {\mathop{\rm int}} \,\,\,\, \Rightarrow \,\,\,\,{x \over 3} = {\mathop{\rm int}} + 1 = {\mathop{\rm int}} \,\,\,\,\left( {{\rm{and}}\,\,x = 3 \cdot {\mathop{\rm int}} + 3 = {\mathop{\rm int}} } \right)\,\,\,\,\, \Rightarrow \,\,\,\,\left\langle {{\rm{YES}}} \right\rangle $$
$$\left( 2 \right)\,\,{{x + 3} \over 6} = {\mathop{\rm int}} \,\,\,\,\mathop \Rightarrow \limits^{ \cdot \,2} \,\,\,\,{{x + 3} \over 3} = {\mathop{\rm int}} \,\,\,\, \Rightarrow \,\,\,\,{x \over 3} = {\mathop{\rm int}} - 1 = {\mathop{\rm int}} \,\,\,\,\left( {{\rm{and}}\,\,x = 3 \cdot {\mathop{\rm int}} - 3 = {\mathop{\rm int}} } \right)\,\,\,\,\, \Rightarrow \,\,\,\,\left\langle {{\rm{YES}}} \right\rangle $$

The correct answer is therefore (D).


We follow the notations and rationale taught in the GMATH method.

Regards,
Fabio.
Fabio Skilnik :: GMATH method creator ( Math for the GMAT)
English-speakers :: https://www.gmath.net
Portuguese-speakers :: https://www.gmath.com.br
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
User avatar
Elite Legendary Member
Posts: 3991
Joined: Fri Jul 24, 2015 2:28 amFollowed by: 37 members
Location: Las Vegas, USA
Thanked: 19 times

by Max@Math Revolution » Mon Feb 04, 2019 4:10 am
=>

Forget conventional ways of solving math questions. For DS problems, the VA (Variable Approach) method is the quickest and easiest way to find the answer without actually solving the problem. Remember that equal numbers of variables and independent equations ensure a solution.

Since we have 1 variable (x) and 0 equations, D is most likely to be the answer. So, we should consider each condition on its own first.

To solve remainder questions, plugging in numbers is recommended.

Condition 1)
If we plug in x = 9, then x - 3 = 6 is divisible by 6 and x is a multiple of 3. Condition 1) is sufficient.

Condition 2)
If we plug in x = 9, then x + 3 = 12 is divisible by 6 and x is a multiple of 3. Condition 2) is sufficient.

Therefore, the answer is D.
Answer: D
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Post new topic Post Reply
• Page 1 of 1