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

Redeem

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.

★★★★★5.0559 reviews
GMATLiveTeach Starts Oct 17
Chris Peckover, Target Test Prep GMAT expert
LIVE ONLINE CLASSES

Get Ready for GMAT Test Day Faster with Live Online Classes

with Chris Peckover, 100th-Percentile GMAT Scorer

Oct 17 · Chris Peckover
Sat · 11:00 AM to 2:00 PM ET
Oct 20 · Chris Peckover
Tue, Thu · 8:00 to 10:00 PM ET
Oct 25 · Josh Braslow
Sun · 1:00 to 4:00 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
EALiveTeachOnDemand 5 seats left Start anytime
EXECUTIVE ASSESSMENT

Target Test Prep EA OnDemand

Self-paced EA prep. Study on your schedule.

Logan Thompson
EXECUTIVE ASSESSMENT

Sep 6 to Dec 6, 2026

with Logan Thompson

165+ EA score guarantee
$05-day trial no automatic billing
Schedule
Sun · 9:30 AM to 12:30 PM ET
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
GMATOnDemand Start 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 559 reviewsTarget Test Prep

Compare the format, schedule, and included access before enrolling. Prices and seat counts shown reflect the supplied offer details.

Data sufficiency

Expert replies
Post new topic Post Reply
Previous Topic Next Topic
Source: — Data Sufficiency |
Master | Next Rank: 500 Posts
Posts: 199
Joined: Sat Apr 26, 2014 10:53 amFollowed by: 4 members
Thanked: 16 times
GMAT Score:780

by 800_or_bust » Thu Jul 07, 2016 6:08 am
Joy Shaha wrote:Q. If k is a positive integer, is k a multiple of 40?
K is a multiple of 4
K is a multiple of 10
(1) NOT SUFFICIENT. K could be 4, which is obviously not a multiple of 40, or K could be 40, which is a multiple of 40.

(2) NOT SUFFICIENT. K could be 10, which is not a multiple of 40. Or K could be 40, which is a multiple of 40.

(1) & (2) Combined. NOT SUFFICIENT. K could be 20 (i.e. 5x4 = 2x10), which is not a multiple of 40. Or K could be 40, which is a multiple of 40.

Answer choice: E
800 or bust!
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
User avatar
Master | Next Rank: 500 Posts
Posts: 410
Joined: Fri Mar 13, 2015 3:36 amFollowed by: 8 members
Location: Worldwide
Thanked: 120 times
GMAT Score:770

by OptimusPrep » Thu Jul 07, 2016 8:47 am
Joy Shaha wrote:Q. If k is a positive integer, is k a multiple of 40?
K is a multiple of 4
K is a multiple of 10
Given: k > 0, integer
Required: Is k a multiple of 40?

Statement 1: k is a multiple of 4
Case 1: k = 8, here k is not a multiple of 40
Case 2: k = 40, here k is a multiple of 40
INSUFFICIENT

Statement 2: k is a multiple of 10
Case 1: k = 20, k is not a multiple of 40
Case 2: k = 40, k is a multiple of 40
INSUFFICIENT

Combining both statements:
k is a multiple of 4 and 10. Hence k will be a multiple of the LCM (20)
Case 1: k = 20, not a multiple of 40
Case 2: k = 40, multiple of 40
INSUFFICIENT

Correct Option: E
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY

GMAT/MBA Expert

User avatar
Elite Legendary Member
Posts: 10392
Joined: Sun Jun 23, 2013 6:38 pmFollowed by: 511 members
Location: Palo Alto, CA
Thanked: 2867 times
GMAT Score:800

by [email protected] » Thu Jul 07, 2016 6:23 pm
Hi Joy Shaha,

This question can be solved rather easily by TESTing VALUES. You might also find it useful to 'brute force' the solution by quickly writing down a bunch of examples so that you can physically 'see' the possibilities:

We're told that K is a positive integer. We're asked if K is a multiple of 40. This is a YES/NO question.

1) K is a multiple of 4

With this Fact, we know that K could be 4, 8, 12, 16, 20, 24, 28, 32, 36, 40....

IF....
K = 4, then the answer to the question is NO.
K = 40, then the answer to the question is YES.
Fact 1 is INSUFFICIENT

2) K is a multiple of 10

With this Fact, we know that K could be 10, 20, 30, 40....

IF....
K = 10, then the answer to the question is NO.
K = 40, then the answer to the question is YES.
Fact 2 is INSUFFICIENT

Combined, we know that K has to be a multiple of 4 AND a multiple of 10. From our two lists of possibilities, we can see two possible values for K that fit BOTH pieces of information:

IF....
K = 20, then the answer to the question is NO.
K = 40, then the answer to the question is YES.
Combined, INSUFFICIENT

Final Answer: E

GMAT assassins aren't born, they're made,
Rich
Contact Rich at [email protected]
Image
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
GMAT Instructor
Posts: 2630
Joined: Wed Sep 12, 2012 3:32 pmFollowed by: 119 members
Location: East Bay all the way
Thanked: 625 times
GMAT Score:780

by Matt@VeritasPrep » Fri Jul 08, 2016 1:56 pm
The basic idea here: if x is a multiple of a and of b, then x is a multiple of the LCM of a and b.

In our case, the LCM of 4 and 10 is 20, so we know k is a multiple of 20. Some multiples of 20 are multiples of 40, some are not, so the answer is E.

This is also a classic example of the too-easy C. If you find yourself thinking, "Ha! Obviously C" ... THE ANSWER IS ALMOST CERTAINLY NOT C! Run screaming from it, and pick something else!
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Master | Next Rank: 500 Posts
Posts: 199
Joined: Sat Apr 26, 2014 10:53 amFollowed by: 4 members
Thanked: 16 times
GMAT Score:780

by 800_or_bust » Fri Jul 08, 2016 2:48 pm
Another example of this question type from the Official Guide: https://gmatclub.com/forum/is-the-positi ... 67953.html
800 or bust!
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Post new topic Post Reply
• Page 1 of 1