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 7 seats left
Chris Peckover
NEXT LIVE COHORT

Oct 13 to Jan 7, 2027

with Chris Peckover

Schedule
Tue, Thu · 8:00 to 10:00 PM ET
Included
40 live hours + 6 months of GMAT OnDemand
  • Live instruction and real-time questions
  • Class recordings and assigned practice
View class & enroll
Limited cohort · enrollment openTarget Test Prep
EALiveTeach 5 seats left
Logan Thompson
EXECUTIVE ASSESSMENT

Sep 6 to Dec 6, 2026

with Logan Thompson

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
Limited cohort · enrollment openTarget 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.

Cat & Owners

Expert replies
Post new topic Post Reply
Previous Topic Next Topic
Master | Next Rank: 500 Posts
Posts: 126
Joined: Sat Jun 07, 2014 5:26 am
Thanked: 3 times
by sandipgumtya » Thu Jun 18, 2015 10:45 pm
In a group of cats and their owners, how
many cats are there?
(1) There are 84 legs in total in the group.
(2) The difference between the number of
cats and their owners is 6.

I cant find reasons to agree with OA-C
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Source: — Data Sufficiency |
Master | Next Rank: 500 Posts
Posts: 363
Joined: Sun Oct 17, 2010 3:24 pmFollowed by: 3 members
Thanked: 115 times

by theCEO » Thu Jun 18, 2015 11:14 pm
sandipgumtya wrote:In a group of cats and their owners, how
many cats are there?
(1) There are 84 legs in total in the group.
(2) The difference between the number of
cats and their owners is 6.

I cant find reasons to agree with OA-C
1) Insufficient on its own.
C = number of cats
o = number of owners
4C + 2o = 84

2) Insufficient on its own
C - o = 6
C = 6 + o

Combining both equation:

The difference between the number of cats and their owners is
C - o = 6
C = 6 + o
o = C - 6

legs from cats = 4 x number of cats = 4C = 4(6+o) = 24 + 4o
legs from owner= 2 x number of owners = 2o = 2(C-6) = 2C - 12

Total legs = 24 + 4o + 2C - 12 = 84
12 + 4o + 2(6+o) = 84
12 + 4o + 12 + 2o = 84
24 + 6o = 84
6o = 60
o = 10

If owner = 10
cats = 10 + 6 = 16

Suffincent. Ans = C
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 2623
Joined: Mon Jun 02, 2008 3:17 amFollowed by: 355 members
Location: Montreal
Thanked: 1090 times
GMAT Score:780

by Ian Stewart » Thu Jun 18, 2015 11:20 pm
I gather we're meant to assume that cats all have 4 legs, and owners all have 2 legs. Then if we have c cats, and ø owners, Statement 1 tells us that

4c + 2ø = 84

which has a lot of possible positive integer solutions, and Statement 2 tells us that

c - ø = 6

which also has a lot of possible positive integer solutions. Taking the two statements together, we have two different linear equations in two unknowns, so we can solve. It's a DS question, so there's no need to actually solve, but if we wanted an answer, we could use substitution, or multiply the second equation by 2 and add the two equations:

4c + 2ø = 84
2c - 2ø = 12
6c = 96
c = 16

At first glance, I thought the meaning of Statement 2 was ambiguous, because it talks about a difference, but doesn't tell us which quantity is larger - it could mean either:

c - ø = 6

or

ø - c = 6

But the question is about owners of cats, and we can't have more owners than cats, because each owner must own at least 1 cat just to be a cat-owner at all. So the equation needs to be the one I used in the solution above, and cannot be ø - c = 6.
For online GMAT math tutoring, or to buy my higher-level Quant books and problem sets, contact me at ianstewartgmat at gmail.com

ianstewartgmat.com
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Master | Next Rank: 500 Posts
Posts: 126
Joined: Sat Jun 07, 2014 5:26 am
Thanked: 3 times

by sandipgumtya » Thu Jun 18, 2015 11:56 pm
I am getting following two cases:

Case 1:Owner-10 and Cat-16
Case 2: Owner-18 and Cat-12.

Both satisfy all the conditions.How can we uniquely determine no of Cats.?
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Master | Next Rank: 500 Posts
Posts: 363
Joined: Sun Oct 17, 2010 3:24 pmFollowed by: 3 members
Thanked: 115 times

by theCEO » Fri Jun 19, 2015 12:21 am
sandipgumtya wrote:I am getting following two cases:

Case 1:Owner-10 and Cat-16
Case 2: Owner-18 and Cat-12.

Both satisfy all the conditions.How can we uniquely determine no of Cats.?
you cannot have more owners than cats.
in other words, you cannot have more cat owners than cats.
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Post new topic Post Reply
• Page 1 of 1