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

It is currently 20 Oct 2018, 10:38

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

In a class of a school, there were 40 percent boys. If some of the stu

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

Hide Tags

Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 50007
In a class of a school, there were 40 percent boys. If some of the stu  [#permalink]

Show Tags

New post 24 Sep 2018, 05:30
00:00
A
B
C
D
E

Difficulty:

  55% (hard)

Question Stats:

54% (02:06) correct 46% (01:35) wrong based on 28 sessions

HideShow timer Statistics

In a class of a school, there were 40 percent boys. If some of the students were transferred to a new section and 30 percent of the transferred students were boys, what was the ratio of the transfer rate for the boys to the transfer rate for the girls?

(A) 1 : 4
(B) 2 : 7
(C) 4 : 9
(D) 9 : 14
(E) 9 : 16

_________________

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

RC Moderator
User avatar
P
Joined: 24 Aug 2016
Posts: 401
Location: Canada
Concentration: Entrepreneurship, Operations
GMAT 1: 630 Q48 V28
GMAT ToolKit User Reviews Badge CAT Tests
Re: In a class of a school, there were 40 percent boys. If some of the stu  [#permalink]

Show Tags

New post 24 Sep 2018, 08:34
Bunuel wrote:
In a class of a school, there were 40 percent boys. If some of the students were transferred to a new section and 30 percent of the transferred students were boys, what was the ratio of the transfer rate for the boys to the transfer rate for the girls?

(A) 1 : 4
(B) 2 : 7
(C) 4 : 9
(D) 9 : 14
(E) 9 : 16


Boys % = 40 ==> Girls% =60
Transferred Boys % =30 ==>Transferred Girls % =70
Hence, Transferred Boys wrt total students % = 40 * 30 & Similarly , Transferred Girls wrt total students % = 60 * 70
Therefore , TB:TG = 40 * 30 : 60 * 70 = 2:7.........Answer B
_________________

Please let me know if I am going in wrong direction.
Thanks in appreciation.

Manager
Manager
avatar
S
Joined: 14 Jun 2018
Posts: 117
Re: In a class of a school, there were 40 percent boys. If some of the stu  [#permalink]

Show Tags

New post 25 Sep 2018, 02:45
Number of Students = 100 ; Boys = 40 ; Girls = 60.
X students were transferred ; 0.3x were boys ; 0.7x were girls
Ratio of transfer rate of boys to girl =[ 0.3x/40 ] / [0.7x/60] = 9 : 14
Manager
Manager
avatar
B
Joined: 24 Dec 2017
Posts: 119
Location: India
Concentration: Strategy, Real Estate
Schools: Johnson '21
Re: In a class of a school, there were 40 percent boys. If some of the stu  [#permalink]

Show Tags

New post 25 Sep 2018, 03:04
Let the total number of students be 100
40% boys=40
60% girls=60

Transferred to new section
30/100x40 = 12 Boys
70/100x60 = 42 girls

New Ratio = Boys/girls = 12/42 =2:7

IMO B

But why is OA D?

Am I doing something wrong or the OA is incorrect?
Manager
Manager
avatar
B
Joined: 24 Dec 2017
Posts: 119
Location: India
Concentration: Strategy, Real Estate
Schools: Johnson '21
Re: In a class of a school, there were 40 percent boys. If some of the stu  [#permalink]

Show Tags

New post 25 Sep 2018, 03:08
pandeyashwin wrote:
Number of Students = 100 ; Boys = 40 ; Girls = 60.
X students were transferred ; 0.3x were boys ; 0.7x were girls
Ratio of transfer rate of boys to girl =[ 0.3x/40 ] / [0.7x/60] = 9 : 14


How did you get 9:14? Could you please explain it?
Veritas Prep GMAT Instructor
User avatar
P
Joined: 16 Oct 2010
Posts: 8399
Location: Pune, India
Re: In a class of a school, there were 40 percent boys. If some of the stu  [#permalink]

Show Tags

New post 25 Sep 2018, 03:35
2
Bunuel wrote:
In a class of a school, there were 40 percent boys. If some of the students were transferred to a new section and 30 percent of the transferred students were boys, what was the ratio of the transfer rate for the boys to the transfer rate for the girls?

(A) 1 : 4
(B) 2 : 7
(C) 4 : 9
(D) 9 : 14
(E) 9 : 16


Say there were 40 boys and 60 girls.
Say 10 students were transferred such that 3 boys and 7 girls were transferred.

Transfer rate of boys = 3/40
Transfer rate of girls = 7/60

Required Ratio = (3/40) / (7/60) = 9:14
_________________

Karishma
Veritas Prep GMAT Instructor

Learn more about how Veritas Prep can help you achieve a great GMAT score by checking out their GMAT Prep Options >

GMAT self-study has never been more personalized or more fun. Try ORION Free!

Manager
Manager
avatar
S
Joined: 14 Jun 2018
Posts: 117
Re: In a class of a school, there were 40 percent boys. If some of the stu  [#permalink]

Show Tags

New post 25 Sep 2018, 06:56
1
ArjunJag1328 wrote:
Let the total number of students be 100
40% boys=40
60% girls=60

Transferred to new section
30/100x40 = 12 Boys
70/100x60 = 42 girls

New Ratio = Boys/girls = 12/42 =2:7

IMO B

But why is OA D?

Am I doing something wrong or the OA is incorrect?

Hey ,
The question says "30 percent of the transferred students were boys" , not "30% of the boys were transferred"
GMAT Club Bot
Re: In a class of a school, there were 40 percent boys. If some of the stu &nbs [#permalink] 25 Sep 2018, 06:56
Display posts from previous: Sort by

In a class of a school, there were 40 percent boys. If some of the stu

  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®.