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

 It is currently 25 Apr 2015, 02:08

### 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 June
Open Detailed Calendar

# Forty percent of the rats included in an experiment were

 Question banks Downloads My Bookmarks Reviews Important topics
Author Message
TAGS:
Manager
Joined: 30 May 2003
Posts: 92
Location: Toronto
Followers: 1

Kudos [?]: 1 [0], given: 0

Forty percent of the rats included in an experiment were [#permalink]  26 Aug 2003, 13:09
00:00

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions
Forty percent of the rats included in an experiment were male rats. If some of the rats died during the experiment and 30 percent of the rats that died were male rats, what was the ratio of the death rate among the male rats to the death rate among the female rats?

Please give complete solution
Manager
Joined: 10 Jun 2003
Posts: 210
Location: Maryland
Followers: 2

Kudos [?]: 4 [0], given: 0

[#permalink]  26 Aug 2003, 13:34
As this is GMAT, you really should put answer choices, but...

Let's pick 100 rats to begin with, 40 are male 60 female.
20 die, so 6 male and 14 female die.

so are you looking for the ratio (6/40)/(14/60)
which reduces to (3/20)/7/30), which again reduces to 9/14?
_________________

Sept 3rd

CEO
Joined: 15 Aug 2003
Posts: 3469
Followers: 61

Kudos [?]: 701 [0], given: 781

[#permalink]  26 Aug 2003, 17:07
mciatto wrote:
As this is GMAT, you really should put answer choices, but...

Let's pick 100 rats to begin with, 40 are male 60 female.
20 die, so 6 male and 14 female die.

so are you looking for the ratio (6/40)/(14/60)
which reduces to (3/20)/7/30), which again reduces to 9/14?

how did you get the total dead rats as 20 ?

thanks
praetorian
Manager
Joined: 10 Jun 2003
Posts: 210
Location: Maryland
Followers: 2

Kudos [?]: 4 [0], given: 0

[#permalink]  26 Aug 2003, 19:04
i picked any number that had 30% as a convenient number. You could have picked anything and still come up with the right answer.
_________________

Sept 3rd

SVP
Joined: 30 Oct 2003
Posts: 1797
Location: NewJersey USA
Followers: 5

Kudos [?]: 41 [0], given: 0

[#permalink]  19 Jan 2004, 19:31
out of 100 rats
M = 40 F = 60
Let D be no of dead rats
so MD = 0.3D and FD = 0.7D
Male death rate = 0.3D/40
Female death rate = 0.7D/60

so ratio of male/female death rate = 0.3D/40 * 60/0.7D = 9/14
Director
Joined: 13 Nov 2003
Posts: 793
Location: BULGARIA
Followers: 1

Kudos [?]: 26 [0], given: 0

[#permalink]  20 Jan 2004, 02:55
I have a little different approach. Please note that 30% of the rats that died were male and 70% are female. The male rats that died are30%x40%=12% and for female rats is 60%x70%=42% or 12/40 death rate for male rats and 42/60 death rate for female rats. The desired ratio is 12/40 divided 42/60 which is 12/40x60/42=3/7. ...may be I am wrong since you all get 9/14 as a ratio
Senior Manager
Joined: 11 Nov 2003
Posts: 355
Location: Illinois
Followers: 1

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

[#permalink]  20 Jan 2004, 09:23
Yet another approach (not much different though)

total number of rats = T

So male rates = 0.4T
Female rates = 0.6T

Total rats that died = D

So number of male rats that died = 0.3D
Number of famale rats that died = 0.7D

Death rate for male rats = 0.3D/0.4T

Death rate for female rats = 0.7D/0.6T

The ration = 3D/4T * 7D/6T = 3/4 * 6/7 = 18/28 = 9/14.
[#permalink] 20 Jan 2004, 09:23
Similar topics Replies Last post
Similar
Topics:
Forty percent of the rats included in an experiment were 3 29 Aug 2008, 14:33
Forty percent of the rats included in an experiment were 2 07 Apr 2008, 19:28
Forty percent of the rats included in an experiment were 1 05 Apr 2008, 23:43
Forty percent of the rats included in an experiment were 2 28 Jul 2007, 23:26
Forty percent of the rats included in an experiment were 3 17 Jul 2005, 05:04
Display posts from previous: Sort by

# Forty percent of the rats included in an experiment were

 Question banks Downloads My Bookmarks Reviews Important topics

 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®.