Find all School-related info fast with the new School-Specific MBA Forum

It is currently 10 Jul 2014, 01:43

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.

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

A computer chip manufacturer expects the ratio of the number

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Manager
Manager
avatar
Joined: 13 Mar 2006
Posts: 76
Followers: 1

Kudos [?]: 2 [0], given: 0

A computer chip manufacturer expects the ratio of the number [#permalink] New post 19 Mar 2006, 02:36
1
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

  5% (low)

Question Stats:

76% (01:39) correct 23% (01:23) wrong based on 26 sessions
Shipment ------No. of Defective Chips/shipment---Total Chips in shipment
S1 -------------- 2 -----------------------------------------------5000
S2 -------------- 5 ------------------------ ----------------------12000
S3 -------------- 6 ----------------------------------------------- 18000
S4 -------------- 4 ----------------------------------------------- 16000

A computer chip manufacturer expects the ratio of the number of defective chips to be total number of chips in all future shipments equal to the corresponding ratio for shipmemts S1,S2,S3 and S4 comined as shown in the table above. What is the expected number of defective chips in a shipment of 60000 chips?

A. 14
B. 20
C. 22
D. 24
E. 25

OPEN DISCUSSION OF THIS QUESTION IS HERE: a-computer-chip-manufacturer-expects-the-ratio-of-the-number-126050.html
[Reveal] Spoiler: OA

_________________

GMAT by 8th JUL


Last edited by Bunuel on 06 May 2012, 01:47, edited 1 time in total.
Edited the question. Topic locked.
Kaplan GMAT Prep Discount CodesKnewton GMAT Discount CodesVeritas Prep GMAT Discount Codes
1 KUDOS received
Manager
Manager
avatar
Joined: 12 Feb 2006
Posts: 71
Followers: 1

Kudos [?]: 2 [1] , given: 0

Re: PS from OG 11th [#permalink] New post 19 Mar 2006, 07:09
1
This post received
KUDOS
foolbox wrote:
shipment, # of defective chips, total # of chips
S1 2 5,000
S2 5 12,000
S3 6 18,000
S4 4 16,000

A computer chip manufacturer expects the ratio of the # of defective chips to the total # of chips in all future shipments to equal the corresponding ratio for shipments S1,S2,S3, and S4 combined, as shown in the table above. What is the expected number of defective chips in a shipment of 60,000 chips?



Say X is the number of defective ships in the shipment of 60,000

we can write out the following equation

2+5+6+4/5,000+12,000+18,000+16,000 = X/60,000

17/51,000 = X/60,000

51,000X= 1,020,000
X= 20
_________________

The greater the sacrifice, the greater the Victory

GMAT Club Legend
GMAT Club Legend
User avatar
Joined: 07 Jul 2004
Posts: 5097
Location: Singapore
Followers: 16

Kudos [?]: 130 [0], given: 0

GMAT Tests User
 [#permalink] New post 19 Mar 2006, 07:10
Total # of defective chips =17
Total # of chips = 51000

# of defective chips in a shipment of 60,000 chips
= (60,000/51,000) * 17
= (60/51) * 17
= (20/17) * 17
= 20
Manager
Manager
avatar
Joined: 13 Mar 2006
Posts: 76
Followers: 1

Kudos [?]: 2 [0], given: 0

Re: PS from OG 11th [#permalink] New post 19 Mar 2006, 08:38
foolbox wrote:
shipment, # of defective chips, total # of chips
S1 2 5,000
S2 5 12,000
S3 6 18,000
S4 4 16,000

A computer chip manufacturer expects the ratio of the # of defective chips to the total # of chips in all future shipments to equal the corresponding ratio for shipments S1,S2,S3, and S4 combined, as shown in the table above. What is the expected number of defective chips in a shipment of 60,000 chips?


How come we can't solve this problem like;

Viewing package S1, and using proportional

2:5,000 = X:60,000

X = 60,000 * 2 / 5,000 = 24

Doesn't that make sense, guys?

pls, correct my misunderstading...
_________________

GMAT by 8th JUL

Manager
Manager
avatar
Joined: 12 Feb 2006
Posts: 71
Followers: 1

Kudos [?]: 2 [0], given: 0

Re: PS from OG 11th [#permalink] New post 19 Mar 2006, 08:44
foolbox wrote:
foolbox wrote:
shipment, # of defective chips, total # of chips
S1 2 5,000
S2 5 12,000
S3 6 18,000
S4 4 16,000

A computer chip manufacturer expects the ratio of the # of defective chips to the total # of chips in all future shipments to equal the corresponding ratio for shipments S1,S2,S3, and S4 combined, as shown in the table above. What is the expected number of defective chips in a shipment of 60,000 chips?


How come we can't solve this problem like;

Viewing package S1, and using proportional

2:5,000 = X:60,000

X = 60,000 * 2 / 5,000 = 24

Doesn't that make sense, guys?

pls, correct my misunderstading...




We can't just take one shipment and make and equation since the stem explicitly states .." in all future shipments to equal the corresponding ratio for shipments S1,S2,S3, and S4 combined".

So you must have all the values in the equation
_________________

The greater the sacrifice, the greater the Victory

Intern
Intern
avatar
Joined: 09 Jun 2005
Posts: 32
Followers: 0

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

 [#permalink] New post 20 Mar 2006, 13:35
The generic formula for such type of ratio problems is

Part1/Part2 = New Part1/Whole

In this problem it will be

Total defective Chips/Total Chips from all shipments = X / 60000

which will be

17/51000 = x/60000
Hence, X=20
Intern
Intern
avatar
Joined: 25 Feb 2008
Posts: 16
Followers: 0

Kudos [?]: 1 [0], given: 0

Re: PS from OG 11th [#permalink] New post 20 Mar 2008, 07:47
Why dont you have to find a common denominator before adding up the ratios? I feel like I am overlookng something easy and fundamental.

Thanks in advance.
Manager
Manager
avatar
Joined: 31 Oct 2007
Posts: 115
Location: Frankfurt, Germany
Followers: 1

Kudos [?]: 21 [0], given: 0

Re: PS from OG 11th [#permalink] New post 20 Mar 2008, 07:59
foolbox wrote:
shipment, # of defective chips, total # of chips
S1 2 5,000
S2 5 12,000
S3 6 18,000
S4 4 16,000

A computer chip manufacturer expects the ratio of the # of defective chips to the total # of chips in all future shipments to equal the corresponding ratio for shipments S1,S2,S3, and S4 combined, as shown in the table above. What is the expected number of defective chips in a shipment of 60,000 chips?


The key phrase in this question is "expects the ratio of the # of defective chips to the total # of chips in all future shipments to equal the corresponding ratio for shipments S1,S2,S3, and S4 combined".

To rephrase the sentense, if there are 17 defects to 51,000 chips, what is the proportion of defect for 60,000 chips?
=> 60,000 / 51,000 * 17 = ~ 20 (19.9999)
_________________

Jimmy Low, Frankfurt, Germany
Blog: http://mytrainmaster.wordpress.com
GMAT Malaysia: http://gmatmalaysia.blogspot.com

3 KUDOS received
Intern
Intern
avatar
Joined: 26 Mar 2010
Posts: 48
Followers: 0

Kudos [?]: 7 [3] , given: 5

Re: Weighted Average [#permalink] New post 25 Oct 2010, 07:04
3
This post received
KUDOS
Summing all the defective chips in the table gives you 2 + 5 + 6 + 4 = 17.
Summing all the total number of chips in each shipment gives you 5k + 12k + 18k + 16k = 51k.

Then, setting up a ratio can help you solve the problem. Since you know there's 17 defective chips in a shipment of 51k, set that equal to x/60k and solve.

17/51k = x/60k
17/51k = 1/3k
1/3k = x/60k
60k/3k = x
x = 20
Intern
Intern
avatar
Joined: 08 Sep 2010
Posts: 4
Followers: 0

Kudos [?]: 0 [0], given: 7

Re: Weighted Average [#permalink] New post 30 Oct 2010, 00:23
I agree with your solution = 20. But the question is:

There are different combination to get 60,000 chips. For example: 1*S3 + 2*S4 + 2*S2. In this way, we ship 60,000 chips with only 6 + 4*2 + 2*2 = 18 defective chips, better than the average of 20.

The question is to find the expected number of defective chips, i guess it assume the minimum #, therefore it might not be 20.

Or i misunderstand the word "EXPECT"
Manager
Manager
avatar
Joined: 25 Jun 2010
Posts: 94
Followers: 1

Kudos [?]: 22 [0], given: 0

GMAT ToolKit User GMAT Tests User
Re: Practice Test 2 Q1 [#permalink] New post 31 Dec 2010, 19:10
There are (2+5+6+4 = 17) defective pieces in shipment of (5000+12000+18000+16000=51000) pieces.
That is equivalent to 1 defective piece/3000 shipment of pieces.

So, in a shipment of 60000 pieces, there will be (1/3000) * 60000 = 20 defective pieces.
1 KUDOS received
Manager
Manager
avatar
Status: Never give up!
Affiliations: Beta Gamma Sigma, Omicron Delta Epsilon, Toastmasters Intl, HHonors
Joined: 04 Nov 2009
Posts: 224
Location: Raleigh-Durham NC
Followers: 2

Kudos [?]: 41 [1] , given: 27

GMAT Tests User
Re: Arith [#permalink] New post 04 May 2011, 11:22
1
This post received
KUDOS
Answer logically B.

1) Sum of chips in all shipments: 51,000
2) Sum of defects in all shipments: 17
3) So, defects:chips is 1:3000

As such, 60,000 chips x (1 defect / 3000 chips) = 20 defects

If there's any hole in my reasoning, I welcome comments. As I can benefit from it too. :-)
(Thanks in advance.)
_________________

= = = = = = = = = =

If you liked my post, please consider a Kudos for me. Thanks!

Director
Director
avatar
Joined: 01 Feb 2011
Posts: 771
Followers: 14

Kudos [?]: 79 [0], given: 42

GMAT Tests User
Re: Weighted Average [#permalink] New post 04 May 2011, 16:40
x/60000 = (2+5+6+4)/51000

=> x = (17/51000)*60000

= 20

Answer is B.
SVP
SVP
avatar
Joined: 16 Nov 2010
Posts: 1692
Location: United States (IN)
Concentration: Strategy, Technology
Followers: 30

Kudos [?]: 272 [0], given: 36

GMAT Tests User Premium Member Reviews Badge
Re: Weighted Average [#permalink] New post 05 May 2011, 06:41
Ratio = 17/510000 (adding the respective columns)

17/51000 = x/60000

=> x = 20

Answer - B
_________________

Formula of Life -> Achievement/Potential = k * Happiness (where k is a constant)

Get the best GMAT Prep Resources with GMAT Club Premium Membership

Manager
Manager
avatar
Joined: 28 May 2011
Posts: 197
Location: United States
Concentration: General Management, International Business
GMAT 1: 720 Q49 V38
GPA: 3.6
WE: Project Management (Computer Software)
Followers: 2

Kudos [?]: 37 [0], given: 7

GMAT Tests User
Re: problem solving questions..GMAT Prep [#permalink] New post 15 Aug 2011, 06:04
key is to understand the meaning of "corresponding ratio for shipments S1, S2, S3, S4 combined"

first I thought it (considering r as the ratio) is equal to = r1+r2+r3+r4, however that gave me answer 84.

So correct interpretation is (take d as nbr of defective and t as nbr of total artifacts ), it is equal to = (d1+d2+d3+d4)/(t1+t2+t3+t4)

so the combined ration comes = 17/51000 = 1/3000

and nbr of defective in a shipment of 60,000 = 60,000 * 1/3000 = 20

answer = B
_________________

-------------------------------------------------------------------------------------------------------------------------------
http://gmatclub.com/forum/a-guide-to-the-official-guide-13-for-gmat-review-134210.html
-------------------------------------------------------------------------------------------------------------------------------

Manager
Manager
avatar
Joined: 12 Feb 2012
Posts: 106
Followers: 1

Kudos [?]: 8 [0], given: 28

Re: A computer chip manufacturer [#permalink] New post 05 May 2012, 07:46
This question is total bullocks. Everyone here took a simple arithmetic average (Total number of Defective)/(Total number of all shipments). I took a weighted average. Obviously the larger shipments should get more weight. Does anyone agree the wording of this question is awkward?
Expert Post
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 18476
Followers: 3185

Kudos [?]: 21156 [0], given: 2534

Re: A computer chip manufacturer [#permalink] New post 06 May 2012, 01:48
Expert's post
alphabeta1234 wrote:
This question is total bullocks. Everyone here took a simple arithmetic average (Total number of Defective)/(Total number of all shipments). I took a weighted average. Obviously the larger shipments should get more weight. Does anyone agree the wording of this question is awkward?


There is nothing wrong with the question or the solutions.

Shipment ------No. of Defective Chips/shipment---Total Chips in shipment
S1 -------------- 2 -----------------------------------------------5000
S2 -------------- 5 ------------------------ ----------------------12000
S3 -------------- 6 ----------------------------------------------- 18000
S4 -------------- 4 ----------------------------------------------- 16000

A computer chip manufacturer expects the ratio of the number of defective chips to be total number of chips in all future shipments equal to the corresponding ratio for shipmemts S1,S2,S3 and S4 comined as shown in the table above. What is the expected number of defective chips in a shipment of 60000 chips?

A. 14
B. 20
C. 22
D. 24
E. 25

Set up equation: \frac{x}{60,000}=\frac{2+5+6+4}{5,000+12,000+18,000+16,000} --> x=20;

Or: 2+5+6+4=17 defective chips in 5,000+12,000+18,000+16,000=51,000 chips, so \frac{17}{51,000}=\frac{1}{3,000}: 1 in 3,000. So, expected number of defective chips in a shipment of 60,000 chips is \frac{60,000}{3,000}=20.

Answer: B.

OPEN DISCUSSION OF THIS QUESTION IS HERE: a-computer-chip-manufacturer-expects-the-ratio-of-the-number-126050.html
_________________

NEW TO MATH FORUM? PLEASE READ THIS: ALL YOU NEED FOR QUANT!!!

PLEASE READ AND FOLLOW: 11 Rules for Posting!!!

RESOURCES: [GMAT MATH BOOK]; 1. Triangles; 2. Polygons; 3. Coordinate Geometry; 4. Factorials; 5. Circles; 6. Number Theory; 7. Remainders; 8. Overlapping Sets; 9. PDF of Math Book; 10. Remainders; 11. GMAT Prep Software Analysis NEW!!!; 12. SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) NEW!!!; 12. Tricky questions from previous years. NEW!!!;

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?
25 extra-hard Quant Tests

Get the best GMAT Prep Resources with GMAT Club Premium Membership

Re: A computer chip manufacturer   [#permalink] 06 May 2012, 01:48
    Similar topics Author Replies Last post
Similar
Topics:
2 Experts publish their posts in the topic In a computer repair shop the ratio of the number of CPUs to gmihir 3 19 May 2012, 08:22
10 Experts publish their posts in the topic A computer chip manufacturer expects the ratio of the number junior 9 25 Oct 2010, 06:40
Experts publish their posts in the topic Number of Chips Skewed 5 24 Nov 2007, 14:36
Gmatprep - computer chips joyce 2 04 Feb 2007, 10:40
CR: computer chips imaru 6 06 Aug 2006, 08:33
Display posts from previous: Sort by

A computer chip manufacturer expects the ratio of the number

  Question banks Downloads My Bookmarks Reviews Important topics  


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

Powered by phpBB © phpBB Group and phpBB SEO

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®.