It is currently 17 Dec 2017, 13:46

### 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

# Each of the students in a certain class received a single

Author Message
TAGS:

### Hide Tags

Director
Joined: 03 Sep 2006
Posts: 862

Kudos [?]: 1133 [2], given: 33

Each of the students in a certain class received a single [#permalink]

### Show Tags

03 Jun 2007, 02:08
2
KUDOS
8
This post was
BOOKMARKED
00:00

Difficulty:

15% (low)

Question Stats:

73% (00:38) correct 27% (00:44) wrong based on 558 sessions

### HideShow timer Statistics

Each of the students in a certain class received a single grade of P, F,or I.What percent of the students in the class were females?

(1) Of those who received a P, 40 percent were females.
(1) Of those who received either an F or I, 80 percent were males.
[Reveal] Spoiler: OA

Kudos [?]: 1133 [2], given: 33

Manager
Joined: 04 May 2007
Posts: 110

Kudos [?]: 3 [1], given: 0

### Show Tags

03 Jun 2007, 15:55
1
KUDOS
LM

I started to use Venn but there was no point IMHO.

We don't know what P or F or I represent. no proportion of the total class was given.

does 40% of P represent 10% of the entire class? 90% of the class?

what does 20% of F or I represent of the total percentage of the class? we dont know. maybe my reasoning is wrong, but that is how I came up with my answer: E

Kudos [?]: 3 [1], given: 0

Manager
Joined: 02 Jan 2007
Posts: 208

Kudos [?]: 11 [4], given: 0

### Show Tags

04 Jun 2007, 07:58
4
KUDOS
1
This post was
BOOKMARKED
Sometimes making a table is easier than getting into Venn diagrams.

I found it easy to get to E after I filled in the empty boxes and still couldnt say I had sufficient information.
Attachments

DS_table.gif [ 1.66 KiB | Viewed 17386 times ]

Kudos [?]: 11 [4], given: 0

Director
Joined: 03 Sep 2006
Posts: 862

Kudos [?]: 1133 [1], given: 33

### Show Tags

04 Jun 2007, 17:13
1
KUDOS
vikramjit_01 wrote:
Sometimes making a table is easier than getting into Venn diagrams.

I found it easy to get to E after I filled in the empty boxes and still couldnt say I had sufficient information.

Thanks! This is what I was looking for in form of either table or venn diagram!

Kudos [?]: 1133 [1], given: 33

Intern
Joined: 28 Apr 2013
Posts: 16

Kudos [?]: 13 [0], given: 3

GMAT Date: 08-03-2013
GPA: 3.3
WE: Supply Chain Management (Military & Defense)
Re: Each of the students in a certain class received a single [#permalink]

### Show Tags

07 Jun 2013, 19:34
So taking 1&2 together we know 80% of those with a fail/incomplete were male so 20% with F&I were female correct? If 40% of those who passed were female, then we can determine that 30% of the students were female.

This was my rationale towards an answer of C. Can anyone explain where I went wrong?

Kudos [?]: 13 [0], given: 3

Math Expert
Joined: 02 Sep 2009
Posts: 42652

Kudos [?]: 135977 [5], given: 12719

Re: Each of the students in a certain class received a single [#permalink]

### Show Tags

08 Jun 2013, 03:42
5
KUDOS
Expert's post
5
This post was
BOOKMARKED
Nwsmith11 wrote:
Each of the students in a certain class received a single grade of P, F,or I.What percent of the students in the class were females?

(1) Of those who received a P, 40 percent were females.
(1) Of those who received either an F or I, 80 percent were males.

So taking 1&2 together we know 80% of those with a fail/incomplete were male so 20% with F&I were female correct? If 40% of those who passed were female, then we can determine that 30% of the students were female.

This was my rationale towards an answer of C. Can anyone explain where I went wrong?

No, the correct answer is E. Consider the following examples:

P=50 and F+I=50, then the # of females = 0.4*50 + 0.2*50 = 30.
P=10 and F+I=90, then the # of females = 0.4*10 + 0.2*90 = 22.

Hope it's clear.
_________________

Kudos [?]: 135977 [5], given: 12719

Senior Manager
Joined: 21 Jan 2010
Posts: 329

Kudos [?]: 231 [0], given: 12

### Show Tags

08 Jun 2013, 17:24
vikramjit_01 wrote:
Sometimes making a table is easier than getting into Venn diagrams.

I found it easy to get to E after I filled in the empty boxes and still couldnt say I had sufficient information.

Kudos [?]: 231 [0], given: 12

Current Student
Joined: 06 Sep 2013
Posts: 1965

Kudos [?]: 759 [1], given: 355

Concentration: Finance
Re: Each of the students in a certain class received a single [#permalink]

### Show Tags

17 Oct 2013, 05:49
1
KUDOS
LM wrote:
Each of the students in a certain class received a single grade of P, F,or I.What percent of the students in the class were females?

(1) Of those who received a P, 40 percent were females.
(1) Of those who received either an F or I, 80 percent were males.

Yup, its E. We can't assume that P,F or I are equally weighted.

Kudos [?]: 759 [1], given: 355

Intern
Joined: 20 Dec 2014
Posts: 22

Kudos [?]: 4 [1], given: 31

Re: Each of the students in a certain class received a single [#permalink]

### Show Tags

17 Mar 2015, 09:47
1
KUDOS
1
This post was
BOOKMARKED
Takeaways: This one was a bit tricky because I approached the problem as a double matrix set but it had 3 variables in the columns and 2 variables(male/female) in the rows. I also attempted to do percentages that lead up to a total but it was getting more complex than I would like. What has helped was recognizing this as a weighted average problem. Therefore an easy method could be:
T (total) = F + P +I
Since we have male and female : T=(M)F+(F)F+(M)P+(F)P+(M)I+(F)I or organize like this T=(M)F+(M)P+(M)I+(F)F+(F)P+(F)I
Translating the statement word by word I got (W/100)T= F? which is the main question we are looking to answer but made it easier on myself by just writing (F/T)*100%=?
1. Of those who received a P, 40% were females
This is clearly insufficient because (F)(P)= .4P and (M)(P)= .6P does not give us any actual numbers to plug in and we still need the other weighted averages.

2. Of those who received either an F or I , 80% were males.
T=.8F+.2F+ (M)P+(F)P+(.8)I+(.2)I
Insufficient because we need actual numbers because weighted averages depend on quantities

(1) and (2)
Insufficient because although we have several percentages we still need quantities because we can have 80/100 total students in f and I be males but then have 4/10 students in P be women.

Bunuel - thoughts?

Kudos [?]: 4 [1], given: 31

EMPOWERgmat Instructor
Status: GMAT Assassin/Co-Founder
Affiliations: EMPOWERgmat
Joined: 19 Dec 2014
Posts: 10419

Kudos [?]: 3700 [0], given: 173

Location: United States (CA)
GMAT 1: 800 Q51 V49
GRE 1: 340 Q170 V170
Re: Each of the students in a certain class received a single [#permalink]

### Show Tags

18 Mar 2015, 19:10
Expert's post
2
This post was
BOOKMARKED
Hi GMAT01,

You ARE correct. When dealing with these type of broad percent-based questions, it's important to be a bit cynical. You do NOT know how many students are in each subgroup, so it would take a LOT of information to answer this question.

As an example, when Fact 1 tells us "Of those who received a P, 40 percent were females", we don't know if 5 people got a P (in which 2 of them were female) or 500 people got a P (in which 200 of them were female). Making the individual group numbers relatively big or relatively small will impact the overall calculation. This can save you some time and effort.

GMAT assassins aren't born, they're made,
Rich
_________________

760+: Learn What GMAT Assassins Do to Score at the Highest Levels
Contact Rich at: Rich.C@empowergmat.com

# Rich Cohen

Co-Founder & GMAT Assassin

Special Offer: Save \$75 + GMAT Club Tests Free
Official GMAT Exam Packs + 70 Pt. Improvement Guarantee
www.empowergmat.com/

***********************Select EMPOWERgmat Courses now include ALL 6 Official GMAC CATs!***********************

Kudos [?]: 3700 [0], given: 173

Intern
Joined: 08 Feb 2014
Posts: 8

Kudos [?]: 6 [0], given: 26

Location: United States
Concentration: Marketing, Operations
GMAT 1: 580 Q36 V34
WE: Information Technology (Computer Software)
Re: Each of the students in a certain class received a single [#permalink]

### Show Tags

20 Sep 2015, 20:02
1
This post was
BOOKMARKED
Bunuel wrote:
Nwsmith11 wrote:
Each of the students in a certain class received a single grade of P, F,or I.What percent of the students in the class were females?

(1) Of those who received a P, 40 percent were females.
(1) Of those who received either an F or I, 80 percent were males.

So taking 1&2 together we know 80% of those with a fail/incomplete were male so 20% with F&I were female correct? If 40% of those who passed were female, then we can determine that 30% of the students were female.

This was my rationale towards an answer of C. Can anyone explain where I went wrong?

No, the correct answer is E. Consider the following examples:

P=50 and F+I=50, then the # of females = 0.4*50 + 0.2*50 = 30.
P=10 and F+I=90, then the # of females = 0.4*10 + 0.2*90 = 22.

Hope it's clear.

@Bunnel - Is it safe to say that in these type of questions until we get the entire class strength in either of the statements, we would always choose E. As stated in your example, we are plugging different set of values and getting different set of answers.

Thanks.

Kudos [?]: 6 [0], given: 26

Director
Joined: 26 Oct 2016
Posts: 689

Kudos [?]: 256 [1], given: 855

Location: United States
Schools: HBS '19
GMAT 1: 770 Q51 V44
GPA: 4
WE: Education (Education)
Re: Each of the students in a certain class received a single [#permalink]

### Show Tags

26 Jan 2017, 07:14
1
KUDOS
1
This post was
BOOKMARKED
This is a weighted average question.

(1) Females make up 40% of group 1 (P)
(2) Females make up 20% of group 2 (F or I)

Together, Female will make up somewhere between 20% and 40% of the whole population. The exact percentage depends on the ratio of group sizes. If there are twice as many people in group 1, then the percentage will be twice as close to group 1 datapoint (40%) as it is to group 2. On the other hand if there are three times as many people in group 2, then the percentage will be three times as close to group 2 datapoint (20%) as it is to group 1. Consider below scenario :-

Let T = total number of students in the class

Each received a single grade so T = F + P +I

? % of T = Females

1. of those who received a P, 40% were females

it doesnt give us the the exact number

2. of those who received either an I or I(I or I ??..may be one of the other two) , 80% were males.

Still it doesnt give us the number of females

so E
_________________

Thanks & Regards,
Anaira Mitch

Kudos [?]: 256 [1], given: 855

Target Test Prep Representative
Affiliations: Target Test Prep
Joined: 04 Mar 2011
Posts: 1810

Kudos [?]: 991 [1], given: 5

Re: Each of the students in a certain class received a single [#permalink]

### Show Tags

30 Jan 2017, 16:55
1
KUDOS
Expert's post
1
This post was
BOOKMARKED
LM wrote:
Each of the students in a certain class received a single grade of P, F,or I.What percent of the students in the class were females?

(1) Of those who received a P, 40 percent were females.
(1) Of those who received either an F or I, 80 percent were males.

We are given that each of the students in a certain class received a single grade of P, F, or I. We can let p = the number of students who received P, f = the number of students who received F, and i = the number of students who received I. Thus, the total number of students in the class is p + f + i. We need to determine the percentage of students who were females.

Statement One Alone:

Of those who received a P, 40 percent were females.

This means 0.4p students are females. However, since we know neither the values of p, f, and i nor the percentage of students who received an F or I, statement one alone is not sufficient to answer the question.

Statement Two Alone:

Of those who received either an F or I, 80 percent were males.

This means 20 percent of the students who received either an F or I were females. In other words, 0.2(f + i) students are females. However, since we know neither the values of p, f, and i nor the percentage of students who received a P, statement two alone is not sufficient to answer the question.

Statements One and Two Together:

From the two statements, we can say that the percentage of students in the class who were females is:

(0.4p + 0.2(f + i))/(p + f + i) x 100

However, since we don’t know the values of p, f, and i, we can’t determine the numerical value of the expression above. Statements one and two together are still not sufficient.

_________________

Jeffery Miller

GMAT Quant Self-Study Course
500+ lessons 3000+ practice problems 800+ HD solutions

Kudos [?]: 991 [1], given: 5

Re: Each of the students in a certain class received a single   [#permalink] 30 Jan 2017, 16:55
Display posts from previous: Sort by