NEW HERE? LEARN MORE
closeclose
Last visit was: 26 Apr 2024, 18:27 It is currently 26 Apr 2024, 18:27
Decision Tracker
My Rewards
New posts
New comers' posts

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.
Go to My Error Log Learn more
Close
Request Expert Reply
Confirm Cancel

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

SORT BY:
Date
Kudos
Tags:
Find Similar Topics 
Show Tags
Hide Tags
User avatar
G
mikemcgarry
Magoosh GMAT Instructor
Joined: 28 Dec 2011
Posts: 4452
Own Kudos [?]: 28575 [9]
Given Kudos: 130
In a certain school, there are 80 Freshmen, 100 Sophomores, and 220 Up [#permalink] New post   20 Oct 2014, 11:50
9
Bookmarks
Expert Reply
00:00
A
B
C
D
E

Difficulty:

35% (medium)

Question Stats:

78% (02:48) correct 22% (02:56) wrong based on 267 sessions
Hide Show 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 :-)
ShowHide Answer
Official Answer
B
avatar
PareshGmat
SVP
SVP
Joined: 27 Dec 2012
Status:The Best Or Nothing
Posts: 1562
Own Kudos [?]: 7208 [4]
Given Kudos: 193
Location: India
Concentration: General Management, Technology
WE:Information Technology (Computer Software)
Send PM
In a certain school, there are 80 Freshmen, 100 Sophomores, and 220 Up [#permalink] New post   20 Oct 2014, 21:09
3
Kudos
1
Bookmarks
Answer = B = 70

Solved using matrix method as below:

Attachment:
mat.png
mat.png [ 6.72 KiB | Viewed 5860 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
avatar
buddyisraelgmat
Manager
Manager
Joined: 14 Jul 2014
Posts: 67
Own Kudos [?]: 95 [1]
Given Kudos: 49
Send PM
Re: In a certain school, there are 80 Freshmen, 100 Sophomores, and 220 Up [#permalink] New post   22 Jan 2015, 23:46
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
avatar
PareshGmat
SVP
SVP
Joined: 27 Dec 2012
Status:The Best Or Nothing
Posts: 1562
Own Kudos [?]: 7208 [1]
Given Kudos: 193
Location: India
Concentration: General Management, Technology
WE:Information Technology (Computer Software)
Send PM
Re: In a certain school, there are 80 Freshmen, 100 Sophomores, and 220 Up [#permalink] New post   23 Jan 2015, 02:30
1
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
User avatar
S
nks2611
Manager
Manager
Joined: 24 Oct 2016
Posts: 196
Own Kudos [?]: 63 [0]
Given Kudos: 89
Location: India
Concentration: Finance, International Business
Schools: IIMB
GMAT 1: 550 Q42 V28
GPA: 3.96
WE:Human Resources (Retail Banking)
Send PM
Re: In a certain school, there are 80 Freshmen, 100 Sophomores, and 220 Up [#permalink] New post   27 Feb 2017, 04:31
the answer should be B we can solve it by suing matrix method .
avatar
B
gatz
Intern
Intern
Joined: 11 Sep 2013
Posts: 18
Own Kudos [?]: 19 [0]
Given Kudos: 295
Schools: CBS '19
Send PM
Re: In a certain school, there are 80 Freshmen, 100 Sophomores, and 220 Up [#permalink] New post   18 Aug 2018, 09:22
Please see attached file below
Correct answer is (B) 70
Attachments

ABC.png
ABC.png [ 30.38 KiB | Viewed 3768 times ]

avatar
B
Kritika2008poddar
Intern
Intern
Joined: 17 Aug 2018
Posts: 16
Own Kudos [?]: 6 [0]
Given Kudos: 41
Send PM
Re: In a certain school, there are 80 Freshmen, 100 Sophomores, and 220 Up [#permalink] New post   18 Aug 2018, 10:29
First step is calculating total no. of students which is 400 and then neglecting C for the calculation as it contains only Frshman. Out of A and B we can quickly cal total no. of B which is 0.30 * 400 = 120 and then out of which half is upperman I.e. 60 remaining half is 60 which is divided into 30 and 30

So out of total 100 shopomores 30 are from B so rest are from A i.e. 70

Posted from my mobile device
User avatar
L
ScottTargetTestPrep
Target Test Prep Representative
Joined: 14 Oct 2015
Status:Founder & CEO
Affiliations: Target Test Prep
Posts: 18767
Own Kudos [?]: 22065 [0]
Given Kudos: 283
Location: United States (CA)
Send PM
Re: In a certain school, there are 80 Freshmen, 100 Sophomores, and 220 Up [#permalink] New post   09 Oct 2020, 10:08
Expert Reply
mikemcgarry wrote:
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



Solution:

We see that there are a total of 80 + 100 + 220 = 400 students from the three cities. Thus, 400 x 0.6 = 240 students are from A, 400 x 0.3 = 120 from B, and 400 - 240 - 120 = 40 from C. Since half the students from B are upperclassmen, 120/2 = 60 students from B are upperclassmen. Since the rest are split evenly between the other two grades, 30 are freshmen and 30 are sophomores. Since all the students from C are freshmen, we see that no sophomores (and no upperclassmen) are from C. Thus, the remaining 100 - 30 = 70 sophomores must be from A.

Answer: B
avatar
B
Pranavb1302
Intern
Intern
Joined: 18 Jul 2020
Posts: 16
Own Kudos [?]: 15 [0]
Given Kudos: 17
Location: India
Concentration: Finance, Entrepreneurship
Schools: Wharton '24
GPA: 3.7
Send PM
Re: In a certain school, there are 80 Freshmen, 100 Sophomores, and 220 Up [#permalink] New post   09 Oct 2020, 10:27
First step is calculating total no. of students which is 400 and then neglecting C for the calculation as it contains only Frshman. Out of A and B we can quickly cal total no. of B which is 0.30 * 400 = 120 and then out of which half is upperman I.e. 60 remaining half is 60 which is divided into 30 and 30

So out of total 100 shopomores 30 are from B so rest are from A i.e. 70

Posted from my mobile device
User avatar
B
gmatpro15
Manager
Manager
Joined: 09 Aug 2022
Posts: 86
Own Kudos [?]: 22 [0]
Given Kudos: 48
Location: India
Concentration: General Management, Leadership
GPA: 4
WE:Design (Real Estate)
Send PM
Re: In a certain school, there are 80 Freshmen, 100 Sophomores, and 220 Up [#permalink] New post   18 Aug 2022, 10:01
1. Total Freshmen = 80

2. Total Sophomores = 100

3. Total Upperclassmen = 220

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

5. 60% from A =60100∗400=240=60100∗400=240

6. 30% from B =30100∗400=120=30100∗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
GMAT Club Bot
gmatclubot
Re: In a certain school, there are 80 Freshmen, 100 Sophomores, and 220 Up [#permalink]
18 Aug 2022, 10:01
Moderators:
Bunuel
Math Expert
92948 posts
yashikaaggarwal
Senior Moderator - Masters Forum
3137 posts

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne
Main navigation
GMAT Resources
Partners
MBA Resources
www.gmac.com|www.mba.com | | GMAT Club Rules | Terms and Conditions