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

 It is currently 19 Nov 2018, 11:55

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

Events & Promotions

Events & Promotions in November
PrevNext
SuMoTuWeThFrSa
28293031123
45678910
11121314151617
18192021222324
2526272829301
Open Detailed Calendar
• How to QUICKLY Solve GMAT Questions - GMAT Club Chat

November 20, 2018

November 20, 2018

09:00 AM PST

10:00 AM PST

The reward for signing up with the registration form and attending the chat is: 6 free examPAL quizzes to practice your new skills after the chat.
• The winning strategy for 700+ on the GMAT

November 20, 2018

November 20, 2018

06:00 PM EST

07:00 PM EST

What people who reach the high 700's do differently? We're going to share insights, tips and strategies from data we collected on over 50,000 students who used examPAL.

If f is the function defined by f(x) = 2x for x ≥ 0 and f(x) = x^2 for

Author Message
TAGS:

Hide Tags

Math Expert
Joined: 02 Sep 2009
Posts: 50670
If f is the function defined by f(x) = 2x for x ≥ 0 and f(x) = x^2 for  [#permalink]

Show Tags

07 Nov 2017, 22:59
00:00

Difficulty:

45% (medium)

Question Stats:

67% (01:00) correct 33% (00:57) wrong based on 85 sessions

HideShow timer Statistics

If f is the function defined by f(x) = 2x for x ≥ 0 and f(x) = x^2 for x < 0, what is the value of f(c) ?

(1) |c| = 2

(2) c < 0

_________________
Director
Joined: 18 Aug 2016
Posts: 625
Concentration: Strategy, Technology
GMAT 1: 630 Q47 V29
GMAT 2: 740 Q51 V38
Re: If f is the function defined by f(x) = 2x for x ≥ 0 and f(x) = x^2 for  [#permalink]

Show Tags

07 Nov 2017, 23:10
Bunuel wrote:
If f is the function defined by f(x) = 2x for x ≥ 0 and f(x) = x^2 for x < 0, what is the value of f(c) ?

(1) |c| = 2

(2) c < 0

(1) c an be 2 then f(c) will be 2*2 =4 or c can be -2 then f(c) will be (-2)^2 = 4..sufficient

(2) not sufficient as c^2 will give different results

A
_________________

We must try to achieve the best within us

Thanks
Luckisnoexcuse

Intern
Joined: 28 Dec 2010
Posts: 49
Re: If f is the function defined by f(x) = 2x for x ≥ 0 and f(x) = x^2 for  [#permalink]

Show Tags

08 Nov 2017, 02:55
Luckisnoexcuse wrote:
Bunuel wrote:
If f is the function defined by f(x) = 2x for x ≥ 0 and f(x) = x^2 for x < 0, what is the value of f(c) ?

(1) |c| = 2

(2) c < 0

(1) c an be 2 then f(c) will be 2*2 =4 or c can be -2 then f(c) will be (-2)^2 = 4..sufficient

(2) not sufficient as c^2 will give different results

A

Answer is correct. Explanation is not.

1. Here it means, any positive or negative value of c is 2.
So $$f(c) = c^2$$ when c>0
f(c) = 4
Sufficient.

2. Here c<0. So f(c) = 2c.
when c = -1, f(c) = -2
when c = -2, f(c) = -4
Insufficient.

A.
_________________

_________________________________________

Manager
Joined: 12 Feb 2017
Posts: 69
If f is the function defined by f(x) = 2x for x ≥ 0 and f(x) = x^2 for  [#permalink]

Show Tags

08 Nov 2017, 23:20
1
f(x) = 2x ----- x ≥ 0
f(x) = x^2 ----x<0
f(c)= ?

(1) |c| = 2
this implies c=+2 or c= -2

lets consider c=+2
f(c)= 2*2 = 4

lets consider c=-2
f(c)= (-2)^2 = 4
In any case, we are getting a unique value i.e. 4
Hence Statement 1 is sufficient.

(2) c < 0
This statement gives us an idea about the sign of c, but it does not tell anything about the value of c.
Hence It is not possible to calculate f(c)
Hence, Statement 2 is Insufficient.

Kudos if it helps.
If f is the function defined by f(x) = 2x for x ≥ 0 and f(x) = x^2 for &nbs [#permalink] 08 Nov 2017, 23:20
Display posts from previous: Sort by