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 →

The range of set X is 9 and the range of set Y is 18. Which

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 » Wed Nov 14, 2018 12:22 am

Timer

00:00

Answers

A

0%

B

0%

C

0%

D

0%

E

0%

Stats

Difficulty—

0% CorrectAvg —

0% IncorrectAvg —

[Math Revolution GMAT math practice question]

The range of set X is 9 and the range of set Y is 18. Which of the following cannot be the range of the union of sets X and Y?

A. 9
B. 18
C. 27
D. 36
E. 45
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Source: — Problem Solving |
User avatar
GMAT Instructor
Posts: 1449
Joined: Sat Oct 09, 2010 2:16 pmFollowed by: 33 members
Thanked: 59 times

The range of set X is 9 and the range of set Y is 18. Which

by fskilnik@GMATH » Wed Nov 14, 2018 3:27 am
Max@Math Revolution wrote:[Math Revolution GMAT math practice question]

The range of set X is 9 and the range of set Y is 18. Which of the following cannot be the range of the union of sets X and Y?

A. 9
B. 18
C. 27
D. 36
E. 45
\[?\,\,\,\,:\,\,\,\,{\text{impossible}}\,\,{\text{range}}\left( {X \cup Y} \right)\]
The range of Y guarantees that there are two elements in Y that differ by exactly 18 units.

Those elements are also in the union of X and Y, therefore the range of XUY is at least 18.

The correct answer is therefore (A).


This solution follows 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
Legendary Member
Posts: 2535
Joined: Sun Oct 29, 2017 2:04 pmFollowed by: 6 members

by swerve » Wed Nov 14, 2018 8:17 am
The minimum range will be the maximum of the range of the two sets.

The maximum range is 18 of the sets so the minimum range of two sets is 18.

Now, notice the options all are greater than equal to 18 except option A, hence this is the correct answer.
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 » Fri Nov 16, 2018 2:06 am
=>

The range of a union is greater than or equal to the maximum of the ranges of the two sets. Thus, the range of the union of X and Y is greater than or equal to 18.

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