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.

Thank you for using the timer!
We noticed you are actually not timing your practice. Click the START button first next time you use the timer.
There are many benefits to timing your practice, including:

In a factory that produces computer circuit boards, 4.5 [#permalink]
18 May 2010, 15:59

5

This post was BOOKMARKED

00:00

A

B

C

D

E

Difficulty:

75% (hard)

Question Stats:

53% (02:38) correct
47% (01:27) wrong based on 228 sessions

In a factory that produces computer circuit boards, 4.5 percent of all boards produced are found to be defective and are repaired before being sold, but 10 percent of all defective boards are sold without being repaired. What percentage of boards produced in the factory are defective?

Re: In a factory that produces computer circuit boards [#permalink]
12 Jun 2012, 12:22

1

This post received KUDOS

Just for the sake of some intuition one should consider this:

That actual 4.5 percent figure that got fixed from the entire amount is equal to 90 percent that got fixed. The 4.5 percent here is adjusted to the 10 percent that gets escaped. So the 4.5 percent of all boards that are found to be defective already includes the adjustment that 10 percent escaped. So in other words after 10 percent escapes that figure is 4.5 percent of total boards. So we need to figure out what the original defective boards in percentage were.

As we know 10% escaped and wasn't caught, We also know that when we originally found 4.5% of boards and fixed them before selling them So that 4.5% was in reality only 90% of all defective board since we missed 10% So, 90% of all defective boards = 4.5% of all boards

So, (10% of y + 4.5% of x) = total number of defective boards = y

Key word here "found"

Last edited by iNumbv on 18 Jun 2013, 13:40, edited 1 time in total.

Re: In a factory that produces computer circuit boards [#permalink]
12 Jun 2012, 12:49

i think total cb and defective cb are not required because (X/Y)*(Y/total) is the answer where x is defective and not repaired and y is defective and total is total no of bulbs. _________________

Your KUDOS will keep me inspired in contributing more to this community......

Helpful Geometry formula sheet:best-geometry-93676.html I hope these will help to understand the basic concepts & strategies. Please Click ON KUDOS Button.

Re: In a factory that produces computer circuit boards, 4.5 [#permalink]
27 Aug 2013, 01:52

1

This post received KUDOS

perseverant wrote:

In a factory that produces computer circuit boards, 4.5 percent of all boards produced are found to be defective and are repaired before being sold, but 10 percent of all defective boards are sold without being repaired. What percentage of boards produced in the factory are defective?

A. 4.5% B. 5.0% C. 6.0% D. 10.0% E. 14.5%

1. 10% of defective boards are not repaired . Therefore 90% of defective boards are repaired 2. 90% of defective boards is equal to 4.5% of all boards produced 3 Total percentage of defective boards produced = 4.5/90 * 100 = 5% _________________

Re: In a factory that produces computer circuit boards, 4.5 [#permalink]
12 Feb 2014, 13:17

SravnaTestPrep wrote:

perseverant wrote:

In a factory that produces computer circuit boards, 4.5 percent of all boards produced are found to be defective and are repaired before being sold, but 10 percent of all defective boards are sold without being repaired. What percentage of boards produced in the factory are defective?

A. 4.5% B. 5.0% C. 6.0% D. 10.0% E. 14.5%

1. 10% of defective boards are not repaired . Therefore 90% of defective boards are repaired 2. 90% of defective boards is equal to 4.5% of all boards produced 3 Total percentage of defective boards produced = 4.5/90 * 100 = 5%

Or similarly one can use smart numbers:

Let's say total produced were 1000

So we have that 45 were defective and repaired Since 10% were not repaired, 90% of boards were defective and repaired The 9/10x = 45, where 'x' is the total number of defective boards.

x = 50

Therefore percentage defective 50/1000 = 5%

Hope this clarifies Cheers J

gmatclubot

Re: In a factory that produces computer circuit boards, 4.5
[#permalink]
12 Feb 2014, 13:17