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

 It is currently 03 Jul 2015, 21:22

### 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

# Percentage

Author Message
TAGS:
Senior Manager
Joined: 25 Dec 2003
Posts: 360
Location: India
Followers: 1

Kudos [?]: 17 [0], given: 0

Percentage [#permalink]  13 Jul 2004, 08:24
Perhaps, i wud have asked this question before, tried for a search, cud not get it, Hence I post it here.

In a group of people, there are 50% of men who are below age 40. And 40% of the females are below 40.. If the total people below the age below 40 are 42% of the people, Then how many percent of females are there in total.

_________________

Giving another SHOT

Senior Manager
Joined: 19 May 2004
Posts: 291
Followers: 1

Kudos [?]: 9 [0], given: 0

M - Number of Men.
W - Number of Women.

1 ) M+W = 100. (100%... Easier to work with a number)

42% - are people under 40.

2) 0.5M + 0.4W = 42.

Solving those two equations i got W= 80.
CIO
Joined: 09 Mar 2003
Posts: 463
Followers: 2

Kudos [?]: 35 [0], given: 0

I agree with Dookie - it's 80%. I have a non-algebra approach that works for this exact problem.

Draw a quick diagram putting all the percentages together that looks like this:

40------42-----------50
W_____t_________M

Then see what the differences are between all the numbers and the middle:

40------42-----------50
W__2__t_____8___M

Now make a ratio using the opposite differences:

w:m = 8:2

so w:whole = 8:10 = 80%

It looks like a lot when it's typed out like this, but see the attachment for how simple it is:

This works for every question where they give you the percentage of two distinct groups, and then the combined percentage as well.
Senior Manager
Joined: 25 Dec 2003
Posts: 360
Location: India
Followers: 1

Kudos [?]: 17 [0], given: 0

Dookie, can u explain a little in detail, please.

Thanks bro.
_________________

Giving another SHOT

Manager
Joined: 16 Jan 2004
Posts: 65
Location: NJ
Followers: 1

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

0.5M + 0.4F =0.42(M+F)

solve

F/M = 8/2. Hence 80%
Manager
Joined: 19 Jun 2003
Posts: 151
Followers: 1

Kudos [?]: 11 [0], given: 0

m > men
w > women
t > total

m + w = t
50/100 * m + 40/100 * w = 42/100 * t

This results in w/t = 4/5 ..which equals %80

Hope this is clear!

Senior Manager
Joined: 25 Dec 2003
Posts: 360
Location: India
Followers: 1

Kudos [?]: 17 [0], given: 0

Ian, i am unable to see any attachements. Can u please resend them?.

Thanks mate.
_________________

Giving another SHOT

SVP
Joined: 16 Oct 2003
Posts: 1813
Followers: 4

Kudos [?]: 56 [0], given: 0

80 percent

m + f = 100
0.5m + o.4f = 42
Similar topics Replies Last post
Similar
Topics:
24 Last year the price per share of Stock X increased by k perc 8 25 Mar 2009, 22:06
Percentage 3 16 Dec 2006, 06:37
Gmatprep-Percentage 3 26 Sep 2006, 23:43
Percentage question 4 19 Sep 2006, 17:24
Percentage 3 16 Aug 2006, 16:14
Display posts from previous: Sort by