December 20, 2018 December 20, 2018 10:00 PM PST 11:00 PM PST This is the most inexpensive and attractive price in the market. Get the course now! December 22, 2018 December 22, 2018 07:00 AM PST 09:00 AM PST Attend this webinar to learn how to leverage Meaning and Logic to solve the most challenging Sentence Correction Questions.
Author 
Message 
TAGS:

Hide Tags

Intern
Joined: 02 May 2013
Posts: 24
Concentration: International Business, Technology
WE: Engineering (Aerospace and Defense)

Find the maximum value of f(x) = 183+x, x belongs to R
[#permalink]
Show Tags
Updated on: 15 May 2013, 01:31
Question Stats:
66% (00:59) correct 34% (01:16) wrong based on 1093 sessions
HideShow timer Statistics
Find the maximum value of f(x) = 183+x, x belongs to R A. 12 B. 18 C. 20 D. 15
Official Answer and Stats are available only to registered users. Register/ Login.
Originally posted by ButwhY on 14 May 2013, 17:45.
Last edited by Bunuel on 15 May 2013, 01:31, edited 2 times in total.
Edited the question and moved to PS forum.




Math Expert
Joined: 02 Sep 2009
Posts: 51280

Re: Find the maximum value of f(x) = 183+x, x belongs to R
[#permalink]
Show Tags
15 May 2013, 01:34




VP
Status: Far, far away!
Joined: 02 Sep 2012
Posts: 1062
Location: Italy
Concentration: Finance, Entrepreneurship
GPA: 3.8

Re: Find the maximum value of f(x) = 183+x, x belongs to R
[#permalink]
Show Tags
30 May 2013, 14:17
WholeLottaLove wrote: With numerous problems involving absolute value, we flip the signs inside the absolute value function if we know it to be a negative #. For example, 3x...if we know that X>3 then we: (3x) = 3+x. I'm guessing we don't do that here because in f(x) x cannot be less than 0?
x can be negative, negative numbers belong to R. We can read the question as: Find the maximum value of \(f(x) = 183+x\), x belongs to R Find the maximum value of \(f(x) = 18(num\geq{0})\) Remeber that an abs value is a number positive or equal to zero ( never negative). So what in which case the operation \(18(num\geq{0})\) has the maxvalue? when the \(num\geq{0}\) is 0. Clearly \(180>181\) for example, so the max value is \(18\). For the sake of clarity: This case corespond to x=3, 33=0. For any other value of x the quantity 3x will result in a positive value that you will subtract to 18, obtaining a lesser value (of course).
_________________
It is beyond a doubt that all our knowledge that begins with experience.
Kant , Critique of Pure Reason Tips and tricks: Inequalities , Mixture  Review: MGMAT workshop Strategy: SmartGMAT v1.0  Questions: Verbal challenge SC III CR New SC set out !! , My QuantRules for Posting in the Verbal Forum  Rules for Posting in the Quant Forum[/size][/color][/b]




Intern
Joined: 14 May 2013
Posts: 7
Location: United States
Concentration: Entrepreneurship, General Management

Re: Find the maximum value of f(x) = 183+x, x belongs to R
[#permalink]
Show Tags
14 May 2013, 19:47
Vamshiiitk wrote: Find the maximum value of f(x) = 183+x, x belongs to R a) 12 b)18 c)20 d)15 Answer: b) 18 Reason: We have to find the max. value of f(x). Max value of 183+x will be 18 because the modulus will make 3+x>=0. Lower the value of 3+x, higher the value of 183+x=f(x). The lowest value of a modulus expression is 0, which implies f(x)=180=18.



Intern
Joined: 05 Mar 2013
Posts: 44
Location: India
Concentration: Entrepreneurship, Marketing
GMAT Date: 06052013
GPA: 3.2

Re: Find the maximum value of f(x) = 183+x, x belongs to R
[#permalink]
Show Tags
15 May 2013, 01:52
Vamshiiitk wrote: Find the maximum value of f(x) = 183+x, x belongs to R
A. 12 B. 18 C. 20 D. 15 The maximum value of 18  a where a >= 0 is 18 .The maximum value occurs when a is minimum and 3+x is minimum at 0 .When x = 3. Answer B
_________________
"Kudos" will help me a lot!!!!!!Please donate some!!!
Completed Official Quant Review OG  Quant
In Progress Official Verbal Review OG 13th ed MGMAT IR AWA Structure
Yet to do 100 700+ SC questions MR Verbal MR Quant
Verbal is a ghost. Cant find head and tail of it.



Senior Manager
Joined: 13 May 2013
Posts: 425

Re: Find the maximum value of f(x) = 183+x, x belongs to R
[#permalink]
Show Tags
30 May 2013, 13:21
With numerous problems involving absolute value, we flip the signs inside the absolute value function if we know it to be a negative #. For example, 3x...if we know that X>3 then we: (3x) = 3+x. I'm guessing we don't do that here because in f(x) x cannot be less than 0? psychout wrote: Vamshiiitk wrote: Find the maximum value of f(x) = 183+x, x belongs to R a) 12 b)18 c)20 d)15 Answer: b) 18 Reason: We have to find the max. value of f(x). Max value of 183+x will be 18 because the modulus will make 3+x>=0. Lower the value of 3+x, higher the value of 183+x=f(x). The lowest value of a modulus expression is 0, which implies f(x)=180=18.



Intern
Joined: 20 Nov 2012
Posts: 14
Location: United States
Concentration: Finance, International Business
GMAT Date: 06152013
GPA: 3.75
WE: Information Technology (Computer Software)

Re: Find the maximum value of f(x) = 183+x, x belongs to R
[#permalink]
Show Tags
30 May 2013, 17:17
Find the maximum value of f(x) = 183+x, x belongs to R
A. 12 B. 18 C. 20 D. 15
f(x) will be max when 3+x is minimum , and x= 3 is when it is minimum
Therefore the max value of f(x) = 18



Math Expert
Joined: 02 Sep 2009
Posts: 51280

Re: Find the maximum value of f(x) = 183+x, x belongs to R
[#permalink]
Show Tags
31 May 2013, 01:18
WholeLottaLove wrote: With numerous problems involving absolute value, we flip the signs inside the absolute value function if we know it to be a negative #. For example, 3x...if we know that X>3 then we: (3x) = 3+x. I'm guessing we don't do that here because in f(x) x cannot be less than 0? psychout wrote: Vamshiiitk wrote: Find the maximum value of f(x) = 183+x, x belongs to R a) 12 b)18 c)20 d)15 Answer: b) 18 Reason: We have to find the max. value of f(x). Max value of 183+x will be 18 because the modulus will make 3+x>=0. Lower the value of 3+x, higher the value of 183+x=f(x). The lowest value of a modulus expression is 0, which implies f(x)=180=18. Actually f(x) can be less than 0. For example, if x=20, then f(20)=183+20=5 or if x=25, then f(25)=18325=4. Now, the question asks about the maximum value of f(x)=183+x (f(x) is equal to 18 minus some nonnegative value). To maximize f(x) we need to minimize 3+x. The minimum value of 3+x is 0, thus the maximum value of f(x)=183+x=180=0. Hope it helps. P.S. Notice that f(x) reaches its minimum for x=3 > f(3)=1833=180=0.
_________________
New to the Math Forum? Please read this: Ultimate GMAT Quantitative Megathread  All You Need for Quant  PLEASE READ AND FOLLOW: 12 Rules for Posting!!! Resources: GMAT Math Book  Triangles  Polygons  Coordinate Geometry  Factorials  Circles  Number Theory  Remainders; 8. Overlapping Sets  PDF of Math Book; 10. Remainders  GMAT Prep Software Analysis  SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS)  Tricky questions from previous years.
Collection of Questions: PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.
What are GMAT Club Tests? Extrahard Quant Tests with Brilliant Analytics



Intern
Joined: 19 Jan 2014
Posts: 26

Re: Find the maximum value of f(x) = 183+x, x belongs to R
[#permalink]
Show Tags
05 Feb 2014, 19:50
ButwhY wrote: Find the maximum value of f(x) = 183+x, x belongs to R
A. 12 B. 18 C. 20 D. 15 What does belong to R mean? Thank you.



Math Expert
Joined: 02 Sep 2009
Posts: 51280

Re: Find the maximum value of f(x) = 183+x, x belongs to R
[#permalink]
Show Tags
05 Feb 2014, 22:40



Director
Status: Tutor  BrushMyQuant
Joined: 05 Apr 2011
Posts: 610
Location: India
Concentration: Finance, Marketing
GPA: 3
WE: Information Technology (Computer Software)

Re: Find the maximum value of f(x) = 183+x, x belongs to R
[#permalink]
Show Tags
24 Jun 2015, 19:07
Mixture problems tag is not required in this ButwhY wrote: Find the maximum value of f(x) = 183+x, x belongs to R
A. 12 B. 18 C. 20 D. 15
_________________
Ankit
Check my Tutoring Site > Brush My Quant
GMAT Quant Tutor How to start GMAT preparations? How to Improve Quant Score? Gmatclub Topic Tags Check out my GMAT debrief
How to Solve : Statistics  Reflection of a line  Remainder Problems  Inequalities



NonHuman User
Joined: 09 Sep 2013
Posts: 9207

Re: Find the maximum value of f(x) = 183+x, x belongs to R
[#permalink]
Show Tags
23 Feb 2017, 12:49
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




Re: Find the maximum value of f(x) = 183+x, x belongs to R &nbs
[#permalink]
23 Feb 2017, 12:49






