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 →

\(abc\ne 0\) and \(\dfrac3{a} + \dfrac3{b} = \dfrac3{c}.\) What is the sum \(a+b?\)

Expert replies
Post new topic Post Reply
Previous Topic Next Topic
Moderator
Posts: 2058
Joined: Sun Oct 29, 2017 4:24 amFollowed by: 5 members
Thanked: 1 times
by M7MBA » Sat Jul 25, 2020 2:45 pm

Timer

00:00

Answers

A

B

C

D

E

Stats

Difficulty—

\(abc\ne 0\) and \(\dfrac3{a} + \dfrac3{b} = \dfrac3{c}.\) What is the sum \(a+b?\)

(1) \(ab=c\)

(2) \(ab=ac+bc\)

[spoiler]OA=A[/spoiler]

Source: Veritas Prep
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: 3008
Joined: Mon Aug 22, 2016 6:19 amFollowed by: 34 members
Location: Grand Central / New York
Thanked: 470 times

Re: \(abc\ne 0\) and \(\dfrac3{a} + \dfrac3{b} = \dfrac3{c}.\) What is the sum \(a+b?\)

by Jay@ManhattanReview » Sun Jul 26, 2020 11:33 pm
M7MBA wrote: ↑
Sat Jul 25, 2020 2:45 pm
 \(abc\ne 0\) and \(\dfrac3{a} + \dfrac3{b} = \dfrac3{c}.\) What is the sum \(a+b?\)

(1) \(ab=c\)

(2) \(ab=ac+bc\)

[spoiler]OA=A[/spoiler]

Source: Veritas Prep
So, we know \(\dfrac3{a} + \dfrac3{b} = \dfrac3{c}.\) Taking LCM, we get \(\dfrac {3(a+b)}{ab} = \dfrac3{c}.\)

\(a+b=\dfrac{ab}c\)

Let's take each statement one by one.

(1) \(ab=c\)

\(\dfrac{ab}c=1\)

Thus, \(a+b=\dfrac{ab}c=1\). Sufficient.

(2) \(ab=ac+bc\)

\(\dfrac{ab}c=a+b\)

Insufficient. We already know this.

Correct answer: A

Hope this helps!

-Jay
_________________
Manhattan Review GMAT Prep

Locations: GMAT Prep Atlanta | SAT Prep San Francisco | GMAT Prep USA | TOEFL Prep Minneapolis | 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
Post new topic Post Reply
• Page 1 of 1