NEW HERE? LEARN MORE
close
It is currently 30 Jan 2023, 19:33
Register
GMAT Club Tests
Decision Tracker
My Rewards
New posts
New comers' posts

Close

GMAT Club Daily Prep

Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track
Your Progress

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

Go to My Error Log Learn more
Close

Request Expert Reply

Confirm Cancel

abc≠0 and 3/a + 3/b = 3/c. What is the sum a+b?

5 posts Go to First Unread Post
Print view
NEW TOPIC
POST REPLY
Downloads
My Bookmarks
Reviews
SORT BY:
Date
Kudos
User avatar
L
Bunuel
Math Expert
Joined: 02 Sep 2009
Posts: 88530
CAT Tests Forum Quiz Mode Top Member of the Month
abc≠0 and 3/a + 3/b = 3/c. What is the sum a+b? [#permalink] New post  17 May 2017, 23:29
4
Bookmarks
Expert Reply
Quiz Dashboard Attempt only this question Same topic and source Same topic and difficulty Same source and difficulty Random Chronological Reverse chronological Learn more
00:00
A
B
C
D
E

Difficulty:

35% (medium)

Question Stats:

70% (01:39) correct 30% (01:40) wrong based on 168 sessions

Hide Show timer Statistics

abc≠0 and 3/a + 3/b = 3/c. What is the sum a+b?

(1) ab=c

(2) ab=ac+bc
ShowHide Answer
Official Answer
Official Answer and Stats are available only to registered users. Register/Login.

_________________
New to the GMAT CLUB Forum?

My Signature Questions' Collection:


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics
Signature Read More
Quiz Dashboard Attempt only this question Same topic and source Same topic and difficulty Same source and difficulty Random Chronological Reverse chronological Learn more
avatar
B
obliraj
Intern
Intern
Joined: 26 Jul 2016
Posts: 35
Location: India
Schools: NTU '20 (S) German MBA (S) NUS '21 (S) IIMA PGPX"20 (D) IIMC PGPEX"20 (A)
Re: abc≠0 and 3/a + 3/b = 3/c. What is the sum a+b? [#permalink] New post  17 May 2017, 23:55
1
Kudos
Answer A.

3/a + 3/b = 3/c
1/a + 1/b = 1/c
(a+b)/ab = 1/c
a+b = ab/c
St 1: ab = c ; i.e a+b=1----- sufficient
St 2: ab=ac+bc; ab=c(a+b); a+b=ab/c---- cannot find a+b----- Insufficient.
avatar
S
Nunuboy1994
Director
Director
Joined: 12 Nov 2016
Posts: 580
Location: United States
Schools: Yale '18
GMAT 1: 650 Q43 V37
GRE 1: Q157 V158
GPA: 2.66
Re: abc≠0 and 3/a + 3/b = 3/c. What is the sum a+b? [#permalink] New post  20 May 2017, 06:37
obliraj wrote:
Answer A.

3/a + 3/b = 3/c
1/a + 1/b = 1/c
(a+b)/ab = 1/c
a+b = ab/c
St 1: ab = c ; i.e a+b=1----- sufficient
St 2: ab=ac+bc; ab=c(a+b); a+b=ab/c---- cannot find a+b----- Insufficient.


It's because if the we know the product of a and b equals the numerator of 1/c or c then the top we can just set equal to a + b= 1

Hence

A
User avatar
D
abhishekdadarwal2009
Director
Director
Joined: 04 Sep 2015
Posts: 570
Location: India
WE:Information Technology (Computer Software)
Reviews Badge
Re: abc≠0 and 3/a + 3/b = 3/c. What is the sum a+b? [#permalink] New post  05 Feb 2019, 10:49
abc≠0 and 3/a + 3/b = 3/c. What is the sum a+b?

(1) ab=c

(2) ab=ac+bc

solution:
3/a+3/b=3/c =3(a+b)/ab=3/c.

1.ab=c ,substitute in the above equation we get a+b=1.
A is sufficient

2.ab=c(a+b), substitute in equation above, we get 1/c so it provies the same info that we already know. so not sufficient

A is the correct answer.
User avatar
bumpbot
Non-Human User
Joined: 09 Sep 2013
Posts: 26457
Re: abc0 and 3/a + 3/b = 3/c. What is the sum a+b? [#permalink] New post  24 Dec 2022, 03:47
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________
GMAT Books | GMAT Club Tests | Best Prices on GMAT Courses | GMAT Mobile App | Math Resources | Verbal Resources
Signature Read More
GMAT Club Bot
gmatclubot
Re: abc0 and 3/a + 3/b = 3/c. What is the sum a+b? [#permalink]
24 Dec 2022, 03:47
NEW TOPIC
POST REPLY
Downloads
My Bookmarks
Reviews
Moderators:
chetan2u
Math Expert
10660 posts
Bunuel
Math Expert
88530 posts

cron

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne
Main navigation
GMAT Resources
Partners
MBA Resources
www.gmac.com|www.mba.com | | GMAT Club Rules | Terms and Conditions