It is currently 18 Jan 2018, 02:19

### 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

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

# For all x, the expression x* is defined to be ax + a, where a is......

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

### Hide Tags

Manager
Status: Persevere
Joined: 08 Jan 2016
Posts: 123

Kudos [?]: 274 [0], given: 94

Location: Hong Kong
GMAT 1: 750 Q50 V41
GPA: 3.52
For all x, the expression x* is defined to be ax + a, where a is...... [#permalink]

### Show Tags

22 May 2016, 22:00
2
This post was
BOOKMARKED
00:00

Difficulty:

5% (low)

Question Stats:

92% (00:47) correct 8% (00:35) wrong based on 241 sessions

### HideShow timer Statistics

For all $$x$$, the expression $$x^*$$ is defined to be $$ax + a$$, where $$a$$ is a constant. What is the value of $$2^*$$?

(1) $$3^* = 2$$
(2) $$5^* = 3$$
[Reveal] Spoiler: OA

Kudos [?]: 274 [0], given: 94

SVP
Joined: 06 Nov 2014
Posts: 1904

Kudos [?]: 563 [1], given: 23

Re: For all x, the expression x* is defined to be ax + a, where a is...... [#permalink]

### Show Tags

22 May 2016, 23:02
1
This post received
KUDOS
nalinnair wrote:
For all $$x$$, the expression $$x^*$$ is defined to be $$ax + a$$, where $$a$$ is a constant. What is the value of $$2^*$$?

(1) $$3^* = 2$$
(2) $$5^* = 3$$

x* = ax + a = a (x + 1)
2* = ?

Statement 1: 3* = 2
or 3a + a = 2
a = 1/2

Hence 2* = (1/2)*(2 + 1) = 3/2
SUFFICIENT

Statement 2: 5* = 3
Or 5a + a = 3
a = 1/2

Hence 2* = (1/2)*(2 + 1) = 3/2
SUFFICIENT

Correct Option: D

Kudos [?]: 563 [1], given: 23

Current Student
Joined: 02 May 2015
Posts: 260

Kudos [?]: 96 [0], given: 23

Location: South Africa
Concentration: International Business, Organizational Behavior
GPA: 3.49
WE: Web Development (Insurance)
Re: For all x, the expression x* is defined to be ax + a, where a is...... [#permalink]

### Show Tags

24 May 2016, 03:54
Trying to solve these equations is unnecessary and in 90% of DS questions a waste of time

A) 3a + a = 2

Linear eqn with 1 variable, 1 solution. sufficient

2) 5 a + a = 6

Same reasoning as above

Answer : D
_________________

Kudos if I helped

Kudos [?]: 96 [0], given: 23

Intern
Joined: 27 Apr 2015
Posts: 26

Kudos [?]: 3 [0], given: 131

GMAT 1: 370 Q29 V13
For all x, the expression x* is defined to be ax + a, where a is...... [#permalink]

### Show Tags

19 Dec 2017, 06:47
nalinnair wrote:
For all $$x$$, the expression $$x^*$$ is defined to be $$ax + a$$, where $$a$$ is a constant. What is the value of $$2^*$$?

(1) $$3^* = 2$$
(2) $$5^* = 3$$

Given
=>x*=ax+a
=>x*=a(x+1)
Therefore
=>2*=a(2+1)
=>2*=3a ----(1)
so if we can find the value of 'a' we can hav the value of 2*

Now
Statement 1 says 3*=2
3*=4a from (1)
=> 4a=2
=> a=2/4=1/2
sufficient

Statement 2 says 5*=3
5*=6a from (1)
=> 6a=3
=> a=3/6=1/2
sufficient

Therefore option 'D'

Thanks

Last edited by dineshril on 19 Dec 2017, 10:31, edited 1 time in total.

Kudos [?]: 3 [0], given: 131

DS Forum Moderator
Joined: 21 Aug 2013
Posts: 657

Kudos [?]: 212 [1], given: 298

Location: India
Re: For all x, the expression x* is defined to be ax + a, where a is...... [#permalink]

### Show Tags

19 Dec 2017, 07:50
1
This post received
KUDOS
dineshril wrote:
nalinnair wrote:
For all $$x$$, the expression $$x^*$$ is defined to be $$ax + a$$, where $$a$$ is a constant. What is the value of $$2^*$$?

(1) $$3^* = 2$$
(2) $$5^* = 3$$

Given
=>x*=ax+a
=>x*=a(x+1)
Therefore
=>2*=a(2+1)
=>2*=3a ----(1)
so if we can find the value of 'a' we can hav the value of 2*

Now
Statement 1 says 3*=2
3*=4a from (1)
=> 4a=2
=> a=2/4=1/2
sufficient

Statement 2 says 5*=3
5*=6a from (1)
=> 6a=3
=> a=3/6=1/2
sufficient

Therefore option 'E'

Thanks

Hi

Correct solution. But when each statement alone is sufficient to answer a question, the answer is D

I guess that was a typo

Kudos [?]: 212 [1], given: 298

Intern
Joined: 27 Apr 2015
Posts: 26

Kudos [?]: 3 [0], given: 131

GMAT 1: 370 Q29 V13
Re: For all x, the expression x* is defined to be ax + a, where a is...... [#permalink]

### Show Tags

19 Dec 2017, 10:30
amanvermagmat wrote:
dineshril wrote:
nalinnair wrote:
For all $$x$$, the expression $$x^*$$ is defined to be $$ax + a$$, where $$a$$ is a constant. What is the value of $$2^*$$?

(1) $$3^* = 2$$
(2) $$5^* = 3$$

Given
=>x*=ax+a
=>x*=a(x+1)
Therefore
=>2*=a(2+1)
=>2*=3a ----(1)
so if we can find the value of 'a' we can hav the value of 2*

Now
Statement 1 says 3*=2
3*=4a from (1)
=> 4a=2
=> a=2/4=1/2
sufficient

Statement 2 says 5*=3
5*=6a from (1)
=> 6a=3
=> a=3/6=1/2
sufficient

Therefore option 'E'

Thanks

Hi

Correct solution. But when each statement alone is sufficient to answer a question, the answer is D

I guess that was a typo

Hi Aman

Thanks for the correction. Its 'D'

Kudos [?]: 3 [0], given: 131

Re: For all x, the expression x* is defined to be ax + a, where a is......   [#permalink] 19 Dec 2017, 10:30
Display posts from previous: Sort by

# For all x, the expression x* is defined to be ax + a, where a is......

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

 Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.