GMAT Question of the Day - Daily to your Mailbox; hard ones only

 It is currently 15 Oct 2019, 21:49 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

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.  For integers a, b, and c, a/(b-c) = 1. What is the value of (b-c)/b?

 new topic post reply Question banks Downloads My Bookmarks Reviews Important topics
Author Message
TAGS:

Hide Tags

Math Expert V
Joined: 02 Sep 2009
Posts: 58347
For integers a, b, and c, a/(b-c) = 1. What is the value of (b-c)/b?  [#permalink]

Show Tags 00:00

Difficulty:   15% (low)

Question Stats: 79% (01:25) correct 21% (01:45) wrong based on 164 sessions

HideShow timer Statistics

Project DS Butler: Day 28: Data Sufficiency (DS56)

For integers a, b, and c, a/(b-c) = 1. What is the value of (b-c)/b?

(1) a/b = 3/5

(2) a and b have no common factors greater than 1

_________________
Retired Moderator D
Joined: 25 Feb 2013
Posts: 1179
Location: India
GPA: 3.82
For integers a, b, and c, a/(b-c) = 1. What is the value of (b-c)/b?  [#permalink]

Show Tags

2
Bunuel wrote:
For integers a, b, and c, a/(b-c) = 1. What is the value of (b-c)/b?

(1) a/b = 3/5

(2) a and b have no common factors greater than 1

Given $$\frac{a}{(b-c)}=1 => b-c=a$$

to find $$\frac{(b-c)}{b}=\frac{a}{b}$$

Statement 1: Directly provides the answer. Hence Sufficient

Statement 2: when you divide $$a$$ by $$b$$ common factors get cancelled out but the non common factors / primes remain whose information is not provided. So $$\frac{a}{b}$$ cannot be calculated. Insufficient

Option A

Originally posted by niks18 on 06 Oct 2017, 06:43.
Last edited by niks18 on 30 Aug 2019, 05:17, edited 1 time in total.
Manager  G
Joined: 12 Feb 2017
Posts: 70
Re: For integers a, b, and c, a/(b-c) = 1. What is the value of (b-c)/b?  [#permalink]

Show Tags

a,b and c are integers
a/(b-c) = 1
means a= (b-c)
(b-c)/b = ?

stmt 1
a/b = 3/5
substitute a= (b-c)
(b-c)/b = 3/5
Hence Sufficient.

stmt 2
a and b have no common factors greater than 1
means a and b are prime, that does not give us any idea about a/b ratio.
Hence Insufficient.

Answer is Option A.

Kudos if it helps.
Retired Moderator B
Joined: 05 Jul 2006
Posts: 1451
Re: For integers a, b, and c, a/(b-c) = 1. What is the value of (b-c)/b?  [#permalink]

Show Tags

Bunuel wrote:
For integers a, b, and c, a/(b-c) = 1. What is the value of (b-c)/b?

(1) a/b = 3/5

(2) a and b have no common factors greater than 1

A = B-C

What is (b-c)/b , i.e. what is a/b??

from 1

suff

from 2

a, b are co prime ...no mention of values or ratio ( depends on the unknown prime factors of each) .. insuff

A
Manager  B
Joined: 06 Aug 2017
Posts: 79
GMAT 1: 570 Q50 V18 GMAT 2: 610 Q49 V24 GMAT 3: 640 Q48 V29 Re: For integers a, b, and c, a/(b-c) = 1. What is the value of (b-c)/b?  [#permalink]

Show Tags

Bunuel wrote:
For integers a, b, and c, a/(b-c) = 1. What is the value of (b-c)/b?

(1) a/b = 3/5

(2) a and b have no common factors greater than 1

The answer should be A as follows.

Given $$\frac{a}{(b-c)}=1$$

1. Condition A gives \frac{a}{b}=$$3/5$$ == $$a=\frac{3}{5}*b$$
Putting this value of "a" in the given condition we get $$\frac{a}{(b-c)}=1$$==>$$((3/5)*b)/(b-c)=1$$==>$$\frac{b}{(b-c)}$$=$$1*\frac{5}{3}$$==>$$\frac{b}{(b-c)}$$=$$\frac{5}{3}$$==>$$\frac{(b-c)}{b}$$=$$\frac{3}{5}$$
SUFFICIENT

2. a and b have no common factors greater than 1 ==> This neither provide any clue about the value of a and b nor provide any relation between a and b that can be substituted in the given equation to solve.
INSUFFICIENT

Hence answer is A
_________________
-------------------------------------------------------------------------------
Kudos are the only way to tell whether my post is useful.

GMAT PREP 1: Q50 V34 - 700

Veritas Test 1: Q43 V34 - 630
Veritas Test 2: Q46 V30 - 620
Veritas Test 3: Q45 V29 - 610
Veritas Test 4: Q49 V30 - 650

GMAT PREP 2: Q50 V34 - 700

Veritas Test 5: Q47 V33 - 650
Veritas Test 5: Q46 V33 - 650
GMAT Club Legend  V
Joined: 12 Sep 2015
Posts: 4003
Re: For integers a, b, and c, a/(b-c) = 1. What is the value of (b-c)/b?  [#permalink]

Show Tags

Top Contributor
Bunuel wrote:
For integers a, b, and c, a/(b-c) = 1. What is the value of (b-c)/b?

(1) a/b = 3/5

(2) a and b have no common factors greater than 1

Given: a/(b - c) = 1

Target question: What is the value of (b-c)/b ?
This is a good candidate for rephrasing the target question.
Aside: The video below has tips on rephrasing the target question
If a/(b - c) = 1, then we know that a = b - c
The target question asks "What is the value of (b-c)/b ?"
Since a = b - c, we can replace b - c with a to get:
REPHRASED target question: What is the value of a/b ?

Statement 1: a/b = 3/5
Perfect!
The answer to the REPHRASED target question is a/b = 3/5
Since we can answer the REPHRASED target question with certainty, statement 1 is SUFFICIENT

Statement 2: a and b have no common factors greater than 1
There are several values of a and b that satisfy statement 2. Here are two:
Case a: a = 1 and b = 2. In this case, the answer to the REPHRASED target question is a/b = 1/2
Case b: a = 2 and b = 3. In this case, the answer to the REPHRASED target question is a/b = 2/3
Since we cannot answer the REPHRASED target question with certainty, statement 2 is NOT SUFFICIENT

RELATED VIDEO FROM OUR COURSE

_________________ Re: For integers a, b, and c, a/(b-c) = 1. What is the value of (b-c)/b?   [#permalink] 29 Oct 2018, 07:25
Display posts from previous: Sort by

For integers a, b, and c, a/(b-c) = 1. What is the value of (b-c)/b?

 new topic post reply Question banks Downloads My Bookmarks Reviews Important topics

 Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne  