It is currently 23 Feb 2018, 10:43

### 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

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

Author Message
TAGS:

### Hide Tags

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

### Show Tags

20 Oct 2014, 10:50
Expert's post
2
This post was
BOOKMARKED
00:00

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

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

 Magoosh Discount Codes e-GMAT Discount Codes Kaplan GMAT Prep Discount Codes
SVP
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

20 Oct 2014, 20:09
2
KUDOS

Solved using matrix method as below:

Attachment:

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

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

### Show Tags

22 Jan 2015, 22:46
1
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
SVP
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

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

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
Joined: 09 Sep 2013
Posts: 13785
Re: In a certain school, there are 80 Freshmen, 100 Sophomores, and 220 Up [#permalink]

### Show Tags

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.
_________________
Senior Manager
Joined: 24 Oct 2016
Posts: 317
Location: India
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

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