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

It is currently 17 Jul 2018, 06:06

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

Of the 300 employees of a certain company, 65 are accountants. Two emp

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

Hide Tags

Expert Post
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 47037
Of the 300 employees of a certain company, 65 are accountants. Two emp [#permalink]

Show Tags

New post 11 May 2015, 07:58
00:00
A
B
C
D
E

Difficulty:

  75% (hard)

Question Stats:

55% (01:05) correct 45% (01:34) wrong based on 105 sessions

HideShow timer Statistics

Of the 300 employees of a certain company, 65 are accountants. Two employees of the company will be selected at random. Which of the following is closest to the probability that neither of the employees selected will be an accountant?

A 0.3
B 0.4
C 0.5
D 0.6
E 0.7

Kudos for a correct solution.

_________________

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

1 KUDOS received
Manager
Manager
avatar
Joined: 12 Nov 2014
Posts: 62
Re: Of the 300 employees of a certain company, 65 are accountants. Two emp [#permalink]

Show Tags

New post 11 May 2015, 09:44
1
Number of non-accountants = 300 -65 = 235

Probability that neither is an accountant = 235C2 / 300C2
= 0.6 (approx)


Answer : D

Ambarish
_________________

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Kindly press Kudos if the explanation is clear.
Thank you
Ambarish

1 KUDOS received
Current Student
avatar
Joined: 29 Mar 2015
Posts: 44
Location: United States
GMAT ToolKit User Reviews Badge
Re: Of the 300 employees of a certain company, 65 are accountants. Two emp [#permalink]

Show Tags

New post 11 May 2015, 21:26
1
65 accountants -> 235 non accountants.
Probability of selecting 2 non accountants = 235/300*234/299, but because we are looking for an approximation, we can just do 235/300*235/300 => (divide each side by 3) 78.333/100*78.333*100 -> round to 78*78/10000. 78*78 is easy to do on paper (6084), so the answer is 6084/10000, or ~60%, which is D.
1 KUDOS received
Senior Manager
Senior Manager
User avatar
S
Joined: 21 Jan 2015
Posts: 312
Location: India
Concentration: Strategy, Marketing
GMAT 1: 620 Q48 V28
WE: Sales (Consumer Products)
GMAT ToolKit User CAT Tests
Re: Of the 300 employees of a certain company, 65 are accountants. Two emp [#permalink]

Show Tags

New post 11 May 2015, 22:09
1
Bunuel wrote:
Of the 300 employees of a certain company, 65 are accountants. Two employees of the company will be selected at random. Which of the following is closest to the probability that neither of the employees selected will be an accountant?

A 0.3
B 0.4
C 0.5
D 0.6
E 0.7

Kudos for a correct solution.


Ans: D

We can Solve this by two ways:
either find the probability by = 1-(both accountant+atleast one accountant)
or direct from = P(both non accountant)

second is easier but requires calculation if don't do the approximation.
So probability= (235/300)*(234/299) = 0.61
so the answer is D
_________________

--------------------------------------------------------------------
The Mind is Everything, What we Think we Become.
Kudos will encourage many others, like me.
Please Give Kudos Image !!
Thanks :-)

1 KUDOS received
Manager
Manager
User avatar
Joined: 22 Feb 2015
Posts: 56
Location: United States
Concentration: Finance, Operations
GMAT Date: 04-01-2015
GPA: 3.98
Re: Of the 300 employees of a certain company, 65 are accountants. Two emp [#permalink]

Show Tags

New post 11 May 2015, 22:32
1
Total = 300
Accountants = 65
Non Accountants = 300 - 65= 235

Two employees of the company will be selected at random so probability that neither of the employees selected will be an accountant is

235 C 2 / 300 C 2 = 235 * 234 / 300 * 299 = 0.611 ~ 0.6

Hence D 0.6 is the correct answer
_________________

Click +1 KUDOS , You can make me happy with just one click! :-) Thanks

Expert Post
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 47037
Re: Of the 300 employees of a certain company, 65 are accountants. Two emp [#permalink]

Show Tags

New post 18 May 2015, 05:44
Bunuel wrote:
Of the 300 employees of a certain company, 65 are accountants. Two employees of the company will be selected at random. Which of the following is closest to the probability that neither of the employees selected will be an accountant?

A 0.3
B 0.4
C 0.5
D 0.6
E 0.7

Kudos for a correct solution.


OFFICIAL SOLUTION:

There are 300 - 65 = 235 employees who are NOT accountants. Therefore, the probability that neither of the two employees selected being an accountant is:
P = 235/300*234/299 = ~0.8*0.8 = 0.64.

Answer: D.
_________________

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

Expert Post
Top Contributor
CEO
CEO
User avatar
P
Joined: 12 Sep 2015
Posts: 2630
Location: Canada
Re: Of the 300 employees of a certain company, 65 are accountants. Two emp [#permalink]

Show Tags

New post 12 Mar 2018, 08:40
Top Contributor
Bunuel wrote:
Of the 300 employees of a certain company, 65 are accountants. Two employees of the company will be selected at random. Which of the following is closest to the probability that neither of the employees selected will be an accountant?

A 0.3
B 0.4
C 0.5
D 0.6
E 0.7

Kudos for a correct solution.


So, there are 300 employees and 235 of them are NOT accountants.

We can solve the question by applying probability rules

P(neither selection is an accountant) = P(1st selection is not an accountant AND 2nd selection is not an accountant)
= P(1st selection is not an accountant) x P(2nd selection is not an accountant)
= 235/300 x 234/299

IMPORTANT: evaluating this product is a pain. Since the answer choices are reasonably spread apart, we can use estimation
Notice that 235/300 is a little bit less than 240/300 (aka 0.8).
In other words, 235/300 is a little bit less than 0.8
Likewise, 234/299 is a little bit less than 0.8

235/300 x 234/299 ≈ (a little bit less than 0.8) x (a little bit less than 0.8)
a little bit less than 0.64
So, the BEST answer is D

ASIDE: After the first non-accountant is selected, there are 299 employees remaining and there are 234 non-accountants remaining. So,P(2nd selection is not an accountant) = 234/299

Cheers,
Brent
_________________

Brent Hanneson – Founder of gmatprepnow.com

Image

Re: Of the 300 employees of a certain company, 65 are accountants. Two emp   [#permalink] 12 Mar 2018, 08:40
Display posts from previous: Sort by

Of the 300 employees of a certain company, 65 are accountants. Two emp

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

Events & Promotions

PREV
NEXT


cron

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®.