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

It is currently 19 Dec 2018, 07:51

TODAY:

MIT Sloan R1 Decisions - Join MIT Chat for Live Updates | Chat with UCLA Anderson Adcom @9am PT | Chat with Yale SOM R1 Admit 10am PT


Close

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

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

Close

Request Expert Reply

Confirm Cancel
Events & Promotions in December
PrevNext
SuMoTuWeThFrSa
2526272829301
2345678
9101112131415
16171819202122
23242526272829
303112345
Open Detailed Calendar
  • Happy Christmas 20% Sale! Math Revolution All-In-One Products!

     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!
  • Key Strategies to Master GMAT SC

     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.

Machine A produces pencils at a constant rate of 9,000 pencils per hou

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

Hide Tags

Manager
Manager
avatar
Joined: 15 Nov 2006
Posts: 201
Location: Ohio
Machine A produces pencils at a constant rate of 9,000 pencils per hou  [#permalink]

Show Tags

New post Updated on: 06 Oct 2017, 09:01
3
13
00:00
A
B
C
D
E

Difficulty:

  35% (medium)

Question Stats:

70% (01:37) correct 30% (02:19) wrong based on 594 sessions

HideShow timer Statistics

Machine A produces pencils at a constant rate of 9000 pencils per hour, and machine B produces pencils at a constant rate of 7000 pencils per hour. If the two machines together must produce 100,000 pencils and if each machine can operate for at most 8 hours, what is the least amount of time, in hours, that machine B must operate?

A. 4
B. 4 2/3
C. 5 1/3
D. 6
E. 6 1/4

Originally posted by nitinneha on 04 Apr 2007, 16:09.
Last edited by Mahmud6 on 06 Oct 2017, 09:01, edited 1 time in total.
Edited
Most Helpful Expert Reply
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 51307
Re: Machine A produces pencils at a constant rate of 9,000 pencils per hou  [#permalink]

Show Tags

New post 27 Jul 2010, 13:16
4
3
Machine A produces pencils at a constant rate of 9,000 pencils per hour, and machine B produces pencils at a constant rate of 7,000 pencils per hour. If the two machines together must produce 100,000 pencils and if each machine can operate for at most 8 hours, what is the least amount of time, in hours, that machine B must operate?

a) 4
b) 4 and 2/3
c) 5 and 1/3
d) 6
e) 6 and 1/4

To minimize the time that machine B must operate we must maximize the time machine A can operate, so make it operate 8 hours. In 8 hours machine A will produce \(8*9,000 = 72,000\) pencils, so \(100,000 - 72,000 = 28,000\) pencils are left to produce, which can be produced by machine B in \(\frac{28,000}{7,000}=4\) hours.

Answer: A.
_________________

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?
Extra-hard Quant Tests with Brilliant Analytics

General Discussion
Senior Manager
Senior Manager
avatar
Joined: 11 Feb 2007
Posts: 335
Re: Machine A produces pencils at a constant rate of 9,000 pencils per hou  [#permalink]

Show Tags

New post 04 Apr 2007, 22:11
1
2
Ax + Bx = 100,000
x <= 8

Since it's asking for the least amount of time for B, A must work to its maximum.

100,000-(9000*8) = 28,000
28,000/7000 = 4

A.

:)
Intern
Intern
User avatar
Joined: 04 May 2004
Posts: 46
Location: India
Re: Machine A produces pencils at a constant rate of 9,000 pencils per hou  [#permalink]

Show Tags

New post 05 Apr 2007, 21:04
Total target = 100, 000

Since machine A is faster, and max is 8 hours, we shall allow machine A to orun for 8 hours. It shall thus produce 9000 * 8 = 72, 000 pencils.

We are short by 28, 000, machine B can work for 28K/7K = 4 hours to do it.

A
Director
Director
User avatar
Joined: 19 Mar 2007
Posts: 517
Re: Machine A produces pencils at a constant rate of 9,000 pencils per hou  [#permalink]

Show Tags

New post 05 Apr 2007, 22:19
1
9,000 x 8 hours + 7,000 x X hours = 100,000
72,000 + 7,000 x X hours = 100,000
X hours =28,000 / 7,000 = 4

A it is
Manager
Manager
avatar
Joined: 28 Feb 2007
Posts: 187
Location: California
Re: Machine A produces pencils at a constant rate of 9,000 pencils per hou  [#permalink]

Show Tags

New post 05 Apr 2007, 23:51
nitinneha wrote:
Machine A produces pencils at a constant rate of 9000 pencils per hour, and machine B produces pencils at a constant rate of 7000 pencils per hour. If the two machines togather must produce 100,000 pencils and if each machine can operate for at most 8 hours, what is the least amount of time, in hours, that machine B must operate?
A)4
B)4 2/3
C)5 1/3
D)6
E)6 1/4


B should operate for least time so A must run for 8 hours and produce 72K. So remaining 28K will be produced by B in 4 hours
Manager
Manager
User avatar
S
Joined: 22 Jan 2014
Posts: 174
WE: Project Management (Computer Hardware)
Re: Machine A produces pencils at a constant rate of 9,000 pencils per hou  [#permalink]

Show Tags

New post 10 Apr 2015, 06:26
nitinneha wrote:
Machine A produces pencils at a constant rate of 9000 pencils per hour, and machine B produces pencils at a constant rate of 7000 pencils per hour. If the two machines to gather must produce 100,000 pencils and if each machine can operate for at most 8 hours, what is the least amount of time, in hours, that machine B must operate?

A. 4
B. 4 2/3
C. 5 1/3
D. 6
E. 6 1/4


9000x + 7000y = 100000
or 9x + 7y = 100

put options

y = 4 --> x = 8
satisfies.
_________________

Illegitimi non carborundum.

Director
Director
User avatar
Joined: 07 Aug 2011
Posts: 536
Concentration: International Business, Technology
GMAT 1: 630 Q49 V27
GMAT ToolKit User
Re: Machine A produces pencils at a constant rate of 9,000 pencils per hou  [#permalink]

Show Tags

New post 10 Apr 2015, 07:38
nitinneha wrote:
Machine A produces pencils at a constant rate of 9000 pencils per hour, and machine B produces pencils at a constant rate of 7000 pencils per hour. If the two machines to gather must produce 100,000 pencils and if each machine can operate for at most 8 hours, what is the least amount of time, in hours, that machine B must operate?

A. 4
B. 4 2/3
C. 5 1/3
D. 6
E. 6 1/4



we want machine B to work minimum hours , for that we have to make machine A work maximum possible hours i.e. 8.
in 8hrs machine A will produce 72 pencils . now remaining 28 pencils will be produced by machine B in 4hrs .
answer A.
(72 + 28 = 100 ) *1000
_________________

Thanks,
Lucky

_______________________________________________________
Kindly press the Image to appreciate my post !! :-)

Current Student
User avatar
Joined: 18 Oct 2014
Posts: 845
Location: United States
GMAT 1: 660 Q49 V31
GPA: 3.98
GMAT ToolKit User
Re: Machine A produces pencils at a constant rate of 9,000 pencils per hou  [#permalink]

Show Tags

New post 29 Jun 2016, 09:16
nitinneha wrote:
Machine A produces pencils at a constant rate of 9000 pencils per hour, and machine B produces pencils at a constant rate of 7000 pencils per hour. If the two machines to gather must produce 100,000 pencils and if each machine can operate for at most 8 hours, what is the least amount of time, in hours, that machine B must operate?

A. 4
B. 4 2/3
C. 5 1/3
D. 6
E. 6 1/4


In order to have Machine B work the least, we need to make Machine A work the maximum number of hours = 8 hrs

Machine A will produce 8*9000= 72,000 pencils in 8 hrs.

Machine B will have to produce remaining 100,000-72,000= 28,000 pencils.

If Machine B produces 7000 pencils in one hour, it will produce 28,000 pencils in 28,000/7= 4 hrs.

A is the answer
_________________

I welcome critical analysis of my post!! That will help me reach 700+

Manager
Manager
avatar
S
Joined: 24 Oct 2013
Posts: 135
Location: India
Concentration: General Management, Strategy
WE: Information Technology (Computer Software)
Re: Machine A produces pencils at a constant rate of 9,000 pencils per hou  [#permalink]

Show Tags

New post 27 Sep 2016, 00:48
Machine A 8 hr work = 8 * 9000 = 72000
remaining work = 100000-72000 = 28000

B takes 7000 in 1 hour = 28000/7000 = 4 hr
Target Test Prep Representative
User avatar
P
Status: Founder & CEO
Affiliations: Target Test Prep
Joined: 14 Oct 2015
Posts: 4326
Location: United States (CA)
Re: Machine A produces pencils at a constant rate of 9,000 pencils per hou  [#permalink]

Show Tags

New post 05 Jun 2017, 15:13
nitinneha wrote:
Machine A produces pencils at a constant rate of 9000 pencils per hour, and machine B produces pencils at a constant rate of 7000 pencils per hour. If the two machines to gather must produce 100,000 pencils and if each machine can operate for at most 8 hours, what is the least amount of time, in hours, that machine B must operate?

A. 4
B. 4 2/3
C. 5 1/3
D. 6
E. 6 1/4


If machine B’s operational time is to be minimized, we must maximize the time for machine A to operate. Since each machine can operate for at most 8 hours, we can let machine A operate for 8 hours. Since the rate of machine A is 9000 pencils per hour, machine A produces 8 x 9000 = 72,000 pencils, and thus 28,000 pencils are left to be produced.

Thus, it will take machine B 28,000/7,000 = 4 hours to produce the remaining pencils.

Answer: A
_________________

Scott Woodbury-Stewart
Founder and CEO

GMAT Quant Self-Study Course
500+ lessons 3000+ practice problems 800+ HD solutions

Non-Human User
User avatar
Joined: 09 Sep 2013
Posts: 9208
Premium Member
Re: Machine A produces pencils at a constant rate of 9,000 pencils per hou  [#permalink]

Show Tags

New post 12 Aug 2018, 22:42
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

GMAT Club Bot
Re: Machine A produces pencils at a constant rate of 9,000 pencils per hou &nbs [#permalink] 12 Aug 2018, 22:42
Display posts from previous: Sort by

Machine A produces pencils at a constant rate of 9,000 pencils per hou

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


Copyright

GMAT Club MBA Forum Home| About| Terms and Conditions and Privacy Policy| GMAT Club Rules| Contact| Sitemap

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®.