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

 It is currently 16 Jan 2019, 04:23

### 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 January
PrevNext
SuMoTuWeThFrSa
303112345
6789101112
13141516171819
20212223242526
272829303112
Open Detailed Calendar
• ### The winning strategy for a high GRE score

January 17, 2019

January 17, 2019

08:00 AM PST

09:00 AM PST

Learn the winning strategy for a high GRE score — what do people who reach a high score do differently? We're going to share insights, tips and strategies from data we've collected from over 50,000 students who used examPAL.
• ### Free GMAT Strategy Webinar

January 19, 2019

January 19, 2019

07:00 AM PST

09:00 AM PST

Aiming to score 760+? Attend this FREE session to learn how to Define your GMAT Strategy, Create your Study Plan and Master the Core Skills to excel on the GMAT.

# One out of every 1000 computer chips is defective. If 2 out of every 3

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

### Hide Tags

Math Expert
Joined: 02 Sep 2009
Posts: 52140
One out of every 1000 computer chips is defective. If 2 out of every 3  [#permalink]

### Show Tags

07 Jan 2015, 06:32
00:00

Difficulty:

15% (low)

Question Stats:

81% (01:29) correct 19% (01:38) wrong based on 96 sessions

### HideShow timer Statistics

Tough and Tricky questions: Word Problems.

One out of every 1000 computer chips is defective. If 2 out of every 30 defective chips have defective processors and there are 30 defective processors in the first batch, how many computer chips are there in the first batch?

A. 450
B. 900
C. 90,000
D. 450,000
E. 900,000

Kudos for a correct solution.

_________________
Board of Directors
Joined: 01 Sep 2010
Posts: 3288
Re: One out of every 1000 computer chips is defective. If 2 out of every 3  [#permalink]

### Show Tags

07 Jan 2015, 06:51
2
$$\frac{2}{30}$$*x=30 so 450.

$$\frac{1}{1000}$$*x=450 so 450000

D should be the correct answer. Tricky question to figure out.

Regards
_________________
Manager
Joined: 21 Aug 2010
Posts: 174
Location: United States
GMAT 1: 700 Q49 V35
Re: One out of every 1000 computer chips is defective. If 2 out of every 3  [#permalink]

### Show Tags

07 Jan 2015, 10:38
Bunuel wrote:

Tough and Tricky questions: Word Problems.

One out of every 1000 computer chips is defective. If 2 out of every 30 defective chips have defective processors and there are 30 defective processors in the first batch, how many computer chips are there in the first batch?

A. 450
B. 900
C. 90,000
D. 450,000
E. 900,000

Kudos for a correct solution.

1 defective Chip per 1000
2 out of 30 defective chips have defective processors

Defective processors in first batch = 30
Defective chips in first batch = 30 * 30 / 2= 450

1 defective Chip per 1000, so total chips = 450 * 1000 = 450000

Ans D
_________________

-------------------------------------

SVP
Status: The Best Or Nothing
Joined: 27 Dec 2012
Posts: 1823
Location: India
Concentration: General Management, Technology
WE: Information Technology (Computer Software)
Re: One out of every 1000 computer chips is defective. If 2 out of every 3  [#permalink]

### Show Tags

07 Jan 2015, 22:10
1
Answer = D. 450,000

Equation setup would be as follows:

$$\frac{30}{2} * 30 * 1000 = 450000$$

(Defective processor) * (Defective chips) * (Number of chips) = Total chips

Another way

................... Chips ......................... Defective .....................................

..................... 1000 ........................... 1 ....................................

.................... 1000*30 ...................... 30 .......... (To produce 30 defective chips, 30000 regular chips are to be made)

.................... 30000 .......................... 30 .................... 2 (Defective processor) ...........

..................... 30000*15 ...................... 30*15 ............. 30 (Multiplication factor is 15 to produce 30 defective processors)

Chips = 15 * 30000 = 450000
_________________

Kindly press "+1 Kudos" to appreciate

Manager
Joined: 27 Oct 2013
Posts: 210
Location: India
Concentration: General Management, Technology
GMAT Date: 03-02-2015
GPA: 3.88
Re: One out of every 1000 computer chips is defective. If 2 out of every 3  [#permalink]

### Show Tags

08 Jan 2015, 01:17
1
Here we go -

2 out of every 30 defective chips have defective processors

1 out of every 15 defective chips has defective processor

30 out of every 450 defective chips have defective processors

**************************************************************

1 out of every 1000 computer chips is defective

450 out of every 450,000 computer chips are defective

option D
Math Expert
Joined: 02 Sep 2009
Posts: 52140
Re: One out of every 1000 computer chips is defective. If 2 out of every 3  [#permalink]

### Show Tags

09 Jan 2015, 05:54
Bunuel wrote:

Tough and Tricky questions: Word Problems.

One out of every 1000 computer chips is defective. If 2 out of every 30 defective chips have defective processors and there are 30 defective processors in the first batch, how many computer chips are there in the first batch?

A. 450
B. 900
C. 90,000
D. 450,000
E. 900,000

Kudos for a correct solution.

OFFICIAL SOLUTION:

(D) Read the whole question to get the feel of what they are asking you to find. Then start with the smallest amount and work your way outwards. We are told that two out of every 30 defective chips have a defective processor. Let x be the total number of defective processors in the batch. Because we know 2 out of every 30 defective chips will have defective processors, and the total number of defective processors in the batch is 30, we can write out an equation: (2/30)x = 30. This can be simplified to (1/15)x = 30. Multiplying each side by 15, we arrive at x = 450. This tells us that there are 450 defective chips in the whole batch. Because we know that 1 out of every 1000 chips is defective, we can set up a proportion. If 1 out of every 1000 chips is defective, then 450 out of y chips would be defective, where y is the total number of chips in the batch. This can be set up as an equation as follows: 1/1000 = 450/y. Solve for y and you will get the total number of chips in the batch: 450,000.

The answer is (D).
_________________
Board of Directors
Status: QA & VA Forum Moderator
Joined: 11 Jun 2011
Posts: 4332
Location: India
GPA: 3.5
WE: Business Development (Commercial Banking)
Re: One out of every 1000 computer chips is defective. If 2 out of every 3  [#permalink]

### Show Tags

03 Jun 2017, 07:22
Bunuel wrote:

Tough and Tricky questions: Word Problems.

One out of every 1000 computer chips is defective. If 2 out of every 30 defective chips have defective processors and there are 30 defective processors in the first batch, how many computer chips are there in the first batch?

A. 450
B. 900
C. 90,000
D. 450,000
E. 900,000

Kudos for a correct solution.

Chips = 1000 , Defective Chips = 1
Chips = 30000 , Defective Chips = 30

Quote:
If 2 out of every 30 defective chips have defective processors

Chips = 30000 , Defective Chips = 30 , Defective Processors = 2

Quote:
there are 30 defective processors in the first batch, how many computer chips are there in the first batch?

When there are 2 Defective processors there are 30,000 chips
When there is 1 Defective processors there are 30,000/2 chips
When there are 30 Defective processors there are 30,000/2*30 chips = 45,000 Chips..

Thus, answer must be (D) 450,000
_________________

Thanks and Regards

Abhishek....

PLEASE FOLLOW THE RULES FOR POSTING IN QA AND VA FORUM AND USE SEARCH FUNCTION BEFORE POSTING NEW QUESTIONS

How to use Search Function in GMAT Club | Rules for Posting in QA forum | Writing Mathematical Formulas |Rules for Posting in VA forum | Request Expert's Reply ( VA Forum Only )

Senior SC Moderator
Joined: 22 May 2016
Posts: 2329
One out of every 1000 computer chips is defective. If 2 out of every 3  [#permalink]

### Show Tags

03 Jun 2017, 07:36
Bunuel wrote:

Tough and Tricky questions: Word Problems.

One out of every 1000 computer chips is defective. If 2 out of every 30 defective chips have defective processors and there are 30 defective processors in the first batch, how many computer chips are there in the first batch?

A. 450
B. 900
C. 90,000
D. 450,000
E. 900,000

Kudos for a correct solution.

I thought of this question as a set within a set, which prevented me from choosing trap answer A.

Let D = number of defective parts generally

Let P = number of defective parts with bad processors (P is a subset of D)

Let T be total number of chips
Quote:
One out of every 1000 computer chips is defective.

$$\frac{D}{T}=\frac{1}{1000}$$
Quote:
If 2 out of every 30 defective chips have defective processors

$$\frac{2}{30}$$ or$$\frac{1}{15}$$D are P, or P = $$\frac{1}{15}$$D
Quote:
there are 30 defective PROCESSORS in the first batch

P = 30, substitute that value:

30 = $$\frac{1}{15}$$D

D = 450 in the first batch
Quote:
how many computer chips are there in the first batch?

$$\frac{D}{T}=\frac{1}{1000}$$

$$\frac{450}{T}=\frac{1}{1000}$$

T = 450,000
_________________

Never look down on anybody unless you're helping them up.
--Jesse Jackson

Non-Human User
Joined: 09 Sep 2013
Posts: 9406
Re: One out of every 1000 computer chips is defective. If 2 out of every 3  [#permalink]

### Show Tags

11 Jan 2019, 19:05
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.
_________________
Re: One out of every 1000 computer chips is defective. If 2 out of every 3 &nbs [#permalink] 11 Jan 2019, 19:05
Display posts from previous: Sort by

# One out of every 1000 computer chips is defective. If 2 out of every 3

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

 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®.