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

It is currently 05 Jul 2015, 21:21

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

birds

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Director
Director
avatar
Joined: 17 Oct 2005
Posts: 938
Followers: 1

Kudos [?]: 69 [0], given: 0

birds [#permalink] New post 12 Feb 2006, 16:19
00:00
A
B
C
D
E

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions
a total of 30 percent of the birds included in a certain migration study were male. If some of the birds migrated during the study and 20 percent of the migrating birds were male, what was the ratio of the migration rate for the male birds to the migration rate for the female birds?

(migration rate for birds of a certain sex = no. of birds of that sex migrating/ total no. of birds of that sex)
VP
VP
avatar
Joined: 21 Sep 2003
Posts: 1065
Location: USA
Followers: 3

Kudos [?]: 40 [0], given: 0

 [#permalink] New post 12 Feb 2006, 17:07
Is it 7:12?

Assume
100 birds (30M & 70F)
x migrate.

0.2x = Male & 0.8x=Female

MM = Male migration ratio = 0.2x/30
FM = Female migration ratio = 0.8x/70

MM/FM = [0.2x/30]/[0.8x/70] = 7/12
_________________

"To dream anything that you want to dream, that is the beauty of the human mind. To do anything that you want to do, that is the strength of the human will. To trust yourself, to test your limits, that is the courage to succeed."

- Bernard Edmonds

GMAT Club Legend
GMAT Club Legend
User avatar
Joined: 07 Jul 2004
Posts: 5068
Location: Singapore
Followers: 23

Kudos [?]: 194 [0], given: 0

 [#permalink] New post 12 Feb 2006, 17:40
Assume total in study = y
Female = 0.7y
Male = 0.3y

x migrated during studyg -> 0.2x male, 0.8x female

migration rate for male birds = 0.2x/0.3y
migration rate for female birds = 0.8x/0.7y

Ratios male: female = 0.2x/0.3y * 0.7y/0.8x = 7/12
Senior Manager
Senior Manager
User avatar
Joined: 11 Jan 2006
Posts: 269
Location: Chennai,India
Followers: 1

Kudos [?]: 3 [0], given: 0

 [#permalink] New post 12 Feb 2006, 21:11
first go i got 1/7 , calculation mistake, agree it is 7/12
_________________

vazlkaiye porkalam vazltuthan parkanum.... porkalam maralam porkalthan maruma

Director
Director
avatar
Joined: 17 Oct 2005
Posts: 938
Followers: 1

Kudos [?]: 69 [0], given: 0

 [#permalink] New post 13 Feb 2006, 13:11
the oa is 7/12 great work guys
  [#permalink] 13 Feb 2006, 13:11
    Similar topics Author Replies Last post
Similar
Topics:
1 Experts publish their posts in the topic Of the birds in a particular aviary, 30 are both spotted and xhimi 1 10 Dec 2013, 18:48
1 Experts publish their posts in the topic How likely is a bird to be classified as positive? Anichka 6 16 Nov 2012, 00:56
8 Experts publish their posts in the topic A scientist recorded the number of eggs in each of 10 birds' Bunuel 10 11 Sep 2012, 03:50
A scientist recorded the number of eggs in each of 10 birds TOUGH GUY 2 30 Sep 2006, 15:38
Display posts from previous: Sort by

birds

  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®.