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 →

Set question; Is the solution right?

Expert replies
Post new topic Post Reply
Previous Topic Next Topic
Newbie | Next Rank: 10 Posts
Posts: 6
Joined: Thu May 10, 2012 12:54 pm
by [email protected] » Tue May 15, 2012 12:06 pm
Of the guests at a charity fundraiser, 180 own both a house in the Hamptons and a house in Palm Beach. If not every guest at the fundraiser owns a house in either the Hamptons or Palm Beach, what is the ratio of the number of people who own a house in Palm Beach but not in the Hamptons to the number of people who own a house in the Hamptons but not in Palm Beach?

(1) One-half of the guests own a house in Palm Beach.

(2) Two-thirds of the guests own a house in the Hamptons.











OA = E; but as far as I concern, it should be C; source is manhatten GMAT;

My answer:
X guests = hous in hampton + house in palm beach - hampton & palm
X guests = (2/3)x + (1/3)x - 180 -> sufficient

Pls tell me where I am wrong :(
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Source: — Data Sufficiency |

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 768
Joined: Wed Dec 28, 2011 4:18 pmFollowed by: 140 members
Location: Berkeley, CA
Thanked: 387 times

by Mike@Magoosh » Tue May 15, 2012 12:35 pm
[email protected] wrote:Of the guests at a charity fundraiser, 180 own both a house in the Hamptons and a house in Palm Beach. If not every guest at the fundraiser owns a house in either the Hamptons or Palm Beach, what is the ratio of the number of people who own a house in Palm Beach but not in the Hamptons to the number of people who own a house in the Hamptons but not in Palm Beach?

(1) One-half of the guests own a house in Palm Beach.

(2) Two-thirds of the guests own a house in the Hamptons.

My answer:
X guests = hous in hampton + house in palm beach - hampton & palm
X guests = (2/3)x + (1/3)x - 180 -> sufficient

Pls tell me where I am wrong :(
Hi, there. I'm happy to help! :)

I agree with your basic set up. I am going to use N for the total number of people at the fundraiser.

Statement #1: (1/2)N own in Palm Beach (of course, dahling!)

Statement #2: (2/3)N own in the Hamptoms (who doesn't!)

Both of those are clearly insufficient on their own. Now, together, we can say

(# who own in PB or H) = (1/2)N + (2/3)N - 180

The problem is --- and this is your mistake --- the set "people who own in either the Hamptons or in Palm Beach" is not coextensive with the entire set, and they even say so in the question: "not every guest at the fundraiser owns a house in either the Hamptons or Palm Beach."

Thus,

N = (1/2)N + (2/3)N - 180 + X

where X is the number of those poor unfortunate lowlifes who are so gauche, so unrefined, that they actually don't own a house in either the Hamptons or in Palm Beach. Heavens to Murgatroyd! Dahling, can you even believe there are people like that in the world? :-P OK, sarcasm aside, we have no idea of the count of X, but from the stem, we know it's greater than zero, so that prevents us from solving for N.

Does that make sense? Let me know if you have any more questions.

Mike :-)
Magoosh GMAT Instructor
https://gmat.magoosh.com/
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
User avatar
Legendary Member
Posts: 520
Joined: Sat Apr 28, 2012 9:12 pmFollowed by: 49 members
Thanked: 339 times
GMAT Score:770

by eagleeye » Tue May 15, 2012 12:41 pm
Hi mad-thinkton:

Your mistake lies in assuming that all people at the fund-raiser have at least one house. If this was true, answer would be a C.

Since we don't know how many people have no house of their own, we can't solve for the numbers or the ratio.

Let me know if this helps :)
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Newbie | Next Rank: 10 Posts
Posts: 6
Joined: Thu May 10, 2012 12:54 pm

by [email protected] » Tue May 15, 2012 12:50 pm
Thx guys!!
My bad. I will consider this more carefully :(
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Post new topic Post Reply
• Page 1 of 1