BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem
TTP OnDemand GMAT Video Course
Featured Course

Target Test Prep GMAT OnDemand

Scott Woodbury-Stewart’s private virtual classroom — 400 hours of master-class video lessons for the GMAT Focus Edition.

  • 715+ score guarantee — highest in the industry (99th percentile)
  • 52 chapters · 1,500+ lessons · 4,000+ practice questions
  • 400 hours of video · 1,500+ instructor-led HD smartboard lessons
  • 300,000+ students accepted to Harvard, Stanford, Wharton, Booth & Sloan & more
  • 24/7 live support + weekly Zoom office hours with GMAT instructors
  • TTP AI Assist — 24/7 AI-powered virtual tutor for instant help
  • 1,200+ flashcards + AI-powered study assistant & daily calendar
  • OnDemand, LiveTeach & GMAT Bootcamp formats available
  • Also: GRE, SAT Math & Executive Assessment courses
  • MBA Admissions Consulting now available
  • 🏆 2025 EdTech Breakthrough Award: Test Prep Solution Provider of the Year
  • 200,000+ students served
  • 5-day free trial — $0 to start, no auto-billing, cancel anytime
★★★★★ 5.0 (559 reviews)
130-pt guarantee
$0 to start then $127/mo
Start Free 5-Day Trial Read 559 Reviews →

Maximize the weekly profit

Expert replies
Post new topic Post Reply
Previous Topic Next Topic
Legendary Member
Posts: 641
Joined: Tue Feb 14, 2012 3:52 pmFollowed by: 8 members
Thanked: 11 times
by gmattesttaker2 » Wed Dec 25, 2013 12:12 am
Hello,

Can you please assist with this:

A chair manufacturer can manufacture a maximum of 800 chairs per week. Her profit is given by the equation P = 1/10(600 - x)(x - 10), where P is her profit and x is the number of chairs manufactured during one week. Which of the following represents the number of chairs that will maximize her weekly profit?

A) 300
B) 305
C) 600
D) 610
E) 620

OA: B

I was able to eliminate C, D and E. I was wondering if there is a way to decide between A and B without plugging in the values. I was able to arrive at this parabola equation:

P = -x^2/10 + 61x - 600

I was wondering if there a way from here to find the correct answer.

Thanks a lot,
Sri
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Source: — Problem Solving |
User avatar
Master | Next Rank: 500 Posts
Posts: 490
Joined: Thu Jul 04, 2013 7:30 amFollowed by: 5 members
Location: Chennai, India
Thanked: 83 times

by Uva@90 » Wed Dec 25, 2013 2:12 am
Hi Sri,
As you eliminate C,D,E. We will look into A and B alone,
Since P = 1/10(600 - x)(x - 10)
but, If X=300
P=(300)*(290)------>1
if X=305
P=(295)*(295)------>2

Equation 1 can be written as (295+5)(295-5) => 295^2-5^2
Equation 2 is 295^2
Hence you can eliminate option A
Ans is B

Regards,
Uva.
Known is a drop Unknown is an Ocean
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Legendary Member
Posts: 641
Joined: Tue Feb 14, 2012 3:52 pmFollowed by: 8 members
Thanked: 11 times

by gmattesttaker2 » Wed Dec 25, 2013 6:35 pm
Uva@90 wrote:Hi Sri,
As you eliminate C,D,E. We will look into A and B alone,
Since P = 1/10(600 - x)(x - 10)
but, If X=300
P=(300)*(290)------>1
if X=305
P=(295)*(295)------>2

Equation 1 can be written as (295+5)(295-5) => 295^2-5^2
Equation 2 is 295^2
Hence you can eliminate option A
Ans is B

Regards,
Uva.

Hello Uva,

Thanks for this awesome approach. This is really cool. Thanks again for all your help.

Best Regards,
Sri
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Post new topic Post Reply
• Page 1 of 1