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 →

If a/b > 4, is a > 8?

Expert replies
Post new topic Post Reply
Previous Topic Next Topic
Source: — Data Sufficiency |

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 3008
Joined: Mon Aug 22, 2016 6:19 amFollowed by: 34 members
Location: Grand Central / New York
Thanked: 470 times

by Jay@ManhattanReview » Mon Jan 07, 2019 12:06 am
VJesus12 wrote:If a/b > 4, is a > 8?

(1) b > 2
(2) a > 7

[spoiler]OA=A[/spoiler]

Source: Princeton Review
Given: a/b > 4

We have to determine whether a > 8.

Let's take each statement one by one.

(1) b > 2

Given b > 2 means that b is positive, thus, we can multiply b to both the sides of a/b > 4.

Thus, we have a/b > 4 => (a/b)*b > 4*b => a > 4b. Say b = 2.001, then a > 4*2.001 => a > 8. Suiificient.

(2) a > 7

Case 1: Say a = 7.5 < 8. Thus, from a/b > 4, we have 7.5/b > 4 => 7.5/4 > b. Since b can have any value, it is a valid case. The answer is No.
Case 2: Say a = 10. Thus, from a/b > 4, we have 10/b > 4 => 10/4 > b. Since b can have any value, it is a valid case. The answer is Yes.

No unique answer. Insufficient.

The correct answer: A

Hope this helps!

-Jay
_________________
Manhattan Review

Locations: Manhattan Review Malleswaram | GMAT Prep Vijayawada | GRE Prep Mumbai | New Delhi GRE Coaching | and many more...

Schedule your free consultation with an experienced GMAT Prep Advisor! Click here.
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
User avatar
GMAT Instructor
Posts: 1449
Joined: Sat Oct 09, 2010 2:16 pmFollowed by: 33 members
Thanked: 59 times

by fskilnik@GMATH » Mon Jan 07, 2019 3:40 am
VJesus12 wrote:If a/b > 4, is a > 8?

(1) b > 2
(2) a > 7
Source: Princeton Review
$${a \over b} > 4$$
$$a\,\,\mathop > \limits^? \,\,8$$
$$\left( 1 \right)\,\,\,\left\{ \matrix{
\,b > 2 \hfill \cr
\,{a \over b} > 4 \hfill \cr} \right.\,\,\,\,\,\,\, \Rightarrow \,\,\,\,\,a\,\,\, = \,\,\,b \cdot {a \over b}\,\,\, > \,\,\,2 \cdot 4\,\,\, = \,\,\,8\,\,\,\,\,\,\, \Rightarrow \,\,\,\,{\rm{SUFF}}.\,\,$$
$$\left( 2 \right)\,\,a > 7\,\,\,\left\{ \matrix{
\,{\rm{Take}}\,\,\left( {a,b} \right) = \left( {8,1} \right)\,\,\,\, \Rightarrow \,\,\,\left\langle {{\rm{NO}}} \right\rangle \,\, \hfill \cr
\,{\rm{Take}}\,\,\left( {a,b} \right) = \left( {9,1} \right)\,\,\,\, \Rightarrow \,\,\,\left\langle {{\rm{YES}}} \right\rangle \,\, \hfill \cr} \right.$$


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
Post new topic Post Reply
• Page 1 of 1