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 →

Ratio and Proportion

Expert replies
Post new topic Post Reply
Previous Topic Next Topic
Senior | Next Rank: 100 Posts
Posts: 73
Joined: Sun May 06, 2012 2:19 am
Location: Cape Town
Thanked: 6 times
by rintoo22 » Thu Mar 21, 2013 6:07 am
The ratio of the number of red cars in a certain parking lot to the number of black cars is 3 to 8. If there are 72 black cars in the lot, how many red cars are there in the lot?

A. 11
B. 15
C. 24
D. 27
E. 32

I am getting an answer of 27 which is not correct. Kindly assist.
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Source: — Problem Solving |

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 511
Joined: Wed Aug 11, 2010 9:47 amFollowed by: 86 members
Location: Delhi, India
Thanked: 344 times

by Anju@Gurome » Thu Mar 21, 2013 6:11 am
rintoo22 wrote:The ratio of the number of red cars in a certain parking lot to the number of black cars is 3 to 8. If there are 72 black cars in the lot, how many red cars are there in the lot?
Say, number of red and black cars are 3x and 8x, respectively.
So, 8x = 72 --> x = 9

Hence, 3x = 3*9 = 27

The correct answer is D.
Last edited by Anju@Gurome on Thu Mar 21, 2013 6:55 am, edited 1 time in total.
Anju Agarwal
Quant Expert, Gurome

Backup Methods : General guide on plugging, estimation etc.
Wavy Curve Method : Solving complex inequalities in a matter of seconds.

§ GMAT with Gurome § Admissions with Gurome § Career Advising with Gurome §
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Senior | Next Rank: 100 Posts
Posts: 73
Joined: Sun May 06, 2012 2:19 am
Location: Cape Town
Thanked: 6 times

by rintoo22 » Thu Mar 21, 2013 6:15 am
Exactly !!!. As much as I thought. But the answer posted in mock test is 24. After your response I am confirmed the 27 is rt. Thanks for the response.
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 16207
Joined: Mon Dec 08, 2008 6:26 pmFollowed by: 1268 members
Location: Vancouver, BC
Thanked: 5254 times
GMAT Score:770

by Brent@GMATPrepNow » Thu Mar 21, 2013 6:15 am
rintoo22 wrote:The ratio of the number of red cars in a certain parking lot to the number of black cars is 3 to 8. If there are 72 black cars in the lot, how many red cars are there in the lot?

A. 11
B. 15
C. 24
D. 27
E. 32

I am getting an answer of 27 which is not correct. Kindly assist.
Use equivalent ratios here
red/black: 3/8 = x/72
Cross multiply to get: 8x = (3)(72)
Divide both sides by 8 to get: x = (3)(9)
x = 27

Cheers,
Brent
Brent Hanneson - Creator of GMATPrepNow.com
Image
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 511
Joined: Wed Aug 11, 2010 9:47 amFollowed by: 86 members
Location: Delhi, India
Thanked: 344 times

by Anju@Gurome » Thu Mar 21, 2013 6:58 am
rintoo22 wrote:But the answer posted in mock test is 24.
That's not possible as ratio of 24 to 72 is 1 to 3, not 3 to 8.
Anju Agarwal
Quant Expert, Gurome

Backup Methods : General guide on plugging, estimation etc.
Wavy Curve Method : Solving complex inequalities in a matter of seconds.

§ GMAT with Gurome § Admissions with Gurome § Career Advising with Gurome §
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Senior | Next Rank: 100 Posts
Posts: 89
Joined: Wed Mar 13, 2013 3:36 amFollowed by: 1 member
Thanked: 10 times

by killerdrummer » Thu Mar 21, 2013 10:07 am
undoubtedly 27!! :)
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Post new topic Post Reply
• Page 1 of 1