It is currently 23 Feb 2018, 10:43

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

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

In a certain school, there are 80 Freshmen, 100 Sophomores, and 220 Up

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

Hide Tags

Expert Post
Magoosh GMAT Instructor
User avatar
G
Joined: 28 Dec 2011
Posts: 4680
In a certain school, there are 80 Freshmen, 100 Sophomores, and 220 Up [#permalink]

Show Tags

New post 20 Oct 2014, 10:50
Expert's post
2
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

  35% (medium)

Question Stats:

78% (02:12) correct 22% (03:08) wrong based on 129 sessions

HideShow timer Statistics

In a certain school, there are 80 Freshmen, 100 Sophomores, and 220 Upperclassmen, drawn from three cities: A, B, and C. Sixty percent of students are from A, 30% from B, the rest from C, and all these students from C are freshmen. Half the student from B are upperclassman, and the rest are split evenly between the other two grades. How many sophomores are from A?
(A) 60
(B) 70
(C) 80
(D) 90
(E) 100


For a discussion of the Double Matrix method for solving questions of this sort, as well as the OE for this question, see:
https://magoosh.com/gmat/2014/gmat-prac ... lems-sets/

Mike :-)
[Reveal] Spoiler: OA

_________________

Mike McGarry
Magoosh Test Prep

Image

Image

Education is not the filling of a pail, but the lighting of a fire. — William Butler Yeats (1865 – 1939)

Magoosh Discount Codese-GMAT Discount CodesKaplan GMAT Prep Discount Codes
2 KUDOS received
SVP
SVP
User avatar
Status: The Best Or Nothing
Joined: 27 Dec 2012
Posts: 1839
Location: India
Concentration: General Management, Technology
WE: Information Technology (Computer Software)
In a certain school, there are 80 Freshmen, 100 Sophomores, and 220 Up [#permalink]

Show Tags

New post 20 Oct 2014, 20:09
2
This post received
KUDOS
Answer = B = 70

Solved using matrix method as below:

Attachment:
mat.png
mat.png [ 6.72 KiB | Viewed 1825 times ]


1. Total Freshmen = 80

2. Total Sophomores = 100

3. Total Upperclassmen = 220

4. Net people = 80+100+220 = 400

5. 60% from A \(= \frac{60}{100} * 400 = 240\)

6. 30% from B \(= \frac{30}{100} * 400 = 120\)

7. Remaining from C = 400 - (240+120) = 40

8. All students of C are Freshmen = 40

9. Half the student from B are upperclassman = 120/2 = 60

10. rest are split evenly between the other two grades = 30

11. rest are split evenly between the other two grades = 30

12. How many sophomores are from A = 100 - 30 = 70
_________________

Kindly press "+1 Kudos" to appreciate :)

1 KUDOS received
Manager
Manager
avatar
Joined: 14 Jul 2014
Posts: 96
Re: In a certain school, there are 80 Freshmen, 100 Sophomores, and 220 Up [#permalink]

Show Tags

New post 22 Jan 2015, 22:46
1
This post received
KUDOS
Ans B = 70

I don't know how to upload the sceenshot but I used 3*3 Matrix

F S U Total
A ? 240
B 30 30 60 120
C 40 0 0 40

Total 80 100 220 400

On solving we get ? = 70
1 KUDOS received
SVP
SVP
User avatar
Status: The Best Or Nothing
Joined: 27 Dec 2012
Posts: 1839
Location: India
Concentration: General Management, Technology
WE: Information Technology (Computer Software)
Re: In a certain school, there are 80 Freshmen, 100 Sophomores, and 220 Up [#permalink]

Show Tags

New post 23 Jan 2015, 01:30
1
This post received
KUDOS
This is a repeated question... have solved it detailed below

Answer = B = 70

in-a-certain-school-there-are-80-freshmen-100-sophomores-and-220-up-187208.html?fl=similar
_________________

Kindly press "+1 Kudos" to appreciate :)

Non-Human User
User avatar
Joined: 09 Sep 2013
Posts: 13785
Premium Member
Re: In a certain school, there are 80 Freshmen, 100 Sophomores, and 220 Up [#permalink]

Show Tags

New post 25 Feb 2017, 05:24
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________

GMAT Books | GMAT Club Tests | Best Prices on GMAT Courses | GMAT Mobile App | Math Resources | Verbal Resources

Senior Manager
Senior Manager
User avatar
S
Joined: 24 Oct 2016
Posts: 317
Location: India
Concentration: Finance, International Business
Schools: IIMB
GMAT 1: 550 Q42 V28
GPA: 3.96
WE: Human Resources (Retail Banking)
Re: In a certain school, there are 80 Freshmen, 100 Sophomores, and 220 Up [#permalink]

Show Tags

New post 27 Feb 2017, 03:31
the answer should be B we can solve it by suing matrix method .
Re: In a certain school, there are 80 Freshmen, 100 Sophomores, and 220 Up   [#permalink] 27 Feb 2017, 03:31
Display posts from previous: Sort by

In a certain school, there are 80 Freshmen, 100 Sophomores, and 220 Up

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  


GMAT Club MBA Forum Home| About| Terms and Conditions| 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®.