It is currently 24 Feb 2018, 07:39

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

At Mnemosyne Middle School, there are 700 students: all the students a

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

Hide Tags

Expert Post
2 KUDOS received
Magoosh GMAT Instructor
User avatar
G
Joined: 28 Dec 2011
Posts: 4680
At Mnemosyne Middle School, there are 700 students: all the students a [#permalink]

Show Tags

New post 28 Feb 2017, 11:25
2
This post received
KUDOS
Expert's post
3
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

  95% (hard)

Question Stats:

53% (03:07) correct 47% (03:19) wrong based on 98 sessions

HideShow timer Statistics

At Mnemosyne Middle School, there are 700 students: all the students are boys or girls in the 4th or 5th grade. There are 320 students in the 4th grade, and there are 210 girls in the 5th grade. Fifty percent of the 5th graders and 40% of the 4th graders take Mandarin Chinese. Ninety 5th grade boys do not take Mandarin Chinese. The number of 4th grade girls taking Mandarin Chinese is less than half of the number of 5th grade girls taking Mandarin Chinese. Which of the following could be the number of 4th grade boys in Mandarin Chinese?

(A) 10
(B) 40
(C) 70
(D) 100
(E) 130


This is one of a set of fifteen challenging GMAT Quant problems. To see the whole collection, as well as the OE for this question, go to:
Challenging GMAT Math Practice Questions

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 CodesManhattan GMAT Discount CodesVeritas Prep GMAT Discount Codes
Expert Post
1 KUDOS received
Math Expert
User avatar
D
Joined: 02 Aug 2009
Posts: 5660
Re: At Mnemosyne Middle School, there are 700 students: all the students a [#permalink]

Show Tags

New post 02 Mar 2017, 05:55
1
This post received
KUDOS
Expert's post
mikemcgarry wrote:
At Mnemosyne Middle School, there are 700 students: all the students are boys or girls in the 4th or 5th grade. There are 320 students in the 4th grade, and there are 210 girls in the 5th grade. Fifty percent of the 5th graders and 40% of the 4th graders take Mandarin Chinese. Ninety 5th grade boys do not take Mandarin Chinese. The number of 4th grade girls taking Mandarin Chinese is less than half of the number of 5th grade girls taking Mandarin Chinese. Which of the following could be the number of 5th grade boys in Mandarin Chinese?

(A) 10
(B) 40
(C) 70
(D) 100
(E) 130


This is one of a set of fifteen challenging GMAT Quant problems. To see the whole collection, as well as the OE for this question, go to:
Challenging GMAT Math Practice Questions

Mike :-)




Hi

A point..
Either the Q has some typo error or it contains unnecessary info and wrong choices

At Mnemosyne Middle School, there are 700 students: all the students are boys or girls in the 4th or 5th grade. There are 320 students in the 4th grade -- So 5th grade has 700-320=380 students
, and there are 210 girls in the 5th grade. --- So total boys in 5th grade are 380-210=170
Fifty percent of the 5th graders and 40% of the 4th graders take Mandarin Chinese. --- In present scenario, nothing comes out of this
Ninety 5th grade boys do not take Mandarin Chinese. ---- So remaining read mandarin Chinese. That is 170-90=80
The number of 4th grade girls taking Mandarin Chinese is less than half of the number of 5th grade girls taking Mandarin Chinese. --Not required
Which of the following could be the number of 5th grade boys in Mandarin Chinese? We have already found it as 80..

80 is not in ANSWER ???
_________________

Absolute modulus :http://gmatclub.com/forum/absolute-modulus-a-better-understanding-210849.html#p1622372
Combination of similar and dissimilar things : http://gmatclub.com/forum/topic215915.html


BANGALORE/-

1 KUDOS received
Manager
Manager
avatar
G
Joined: 28 Jul 2016
Posts: 126
Premium Member
Re: At Mnemosyne Middle School, there are 700 students: all the students a [#permalink]

Show Tags

New post 02 Mar 2017, 06:42
1
This post received
KUDOS
According to OA from Magoosh website - answer is about 4th grade boys taking Mandarin Chinese, not 5th...
https://magoosh.com/gmat/2017/challengi ... questions/
Intern
Intern
avatar
Joined: 28 Jul 2011
Posts: 30
Location: United Kingdom
WE: Corporate Finance (Energy and Utilities)
Re: At Mnemosyne Middle School, there are 700 students: all the students a [#permalink]

Show Tags

New post 02 Mar 2017, 07:01
Is the answer 100? (D)
Attachments

Capture.PNG
Capture.PNG [ 12.36 KiB | Viewed 1556 times ]

Expert Post
Magoosh GMAT Instructor
User avatar
G
Joined: 28 Dec 2011
Posts: 4680
Re: At Mnemosyne Middle School, there are 700 students: all the students a [#permalink]

Show Tags

New post 02 Mar 2017, 10:08
chetan2u wrote:
mikemcgarry wrote:
At Mnemosyne Middle School, there are 700 students: all the students are boys or girls in the 4th or 5th grade. There are 320 students in the 4th grade, and there are 210 girls in the 5th grade. Fifty percent of the 5th graders and 40% of the 4th graders take Mandarin Chinese. Ninety 5th grade boys do not take Mandarin Chinese. The number of 4th grade girls taking Mandarin Chinese is less than half of the number of 5th grade girls taking Mandarin Chinese. Which of the following could be the number of 5th grade boys in Mandarin Chinese?

(A) 10
(B) 40
(C) 70
(D) 100
(E) 130


This is one of a set of fifteen challenging GMAT Quant problems. To see the whole collection, as well as the OE for this question, go to:
Challenging GMAT Math Practice Questions

Mike :-)

Hi

A point..
Either the Q has some typo error or it contains unnecessary info and wrong choices

LeonidK wrote:
According to OA from Magoosh website - answer is about 4th grade boys taking Mandarin Chinese, not 5th...

Dear chetan2u & LeonidK,

Thank you very much to both of you! :-) Yes, these tiny typos sometimes are the hardest things to find and notice. Indeed, the prompt question was supposed to be about the number of 4th grade boys in Mandarin.

I corrected the question above and the blog. Thank you very much for finding this typo!

Mike McGarry :-)
_________________

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)

Manager
Manager
User avatar
B
Status: Profile 1
Joined: 20 Sep 2015
Posts: 75
GMAT 1: 690 Q48 V37
GPA: 3.2
WE: Information Technology (Investment Banking)
GMAT ToolKit User
Re: At Mnemosyne Middle School, there are 700 students: all the students a [#permalink]

Show Tags

New post 21 Apr 2017, 10:30
At Mnemosyne Middle School, there are 700 students: all the students are boys or girls in the 4th or 5th grade. There are 320 students in the 4th grade, and there are 210 girls in the 5th grade. Fifty percent of the 5th graders and 40% of the 4th graders take Mandarin Chinese. Ninety 5th grade boys do not take Mandarin Chinese. The number of 4th grade girls taking Mandarin Chinese is less than half of the number of 5th grade girls taking Mandarin Chinese. Which of the following could be the number of 4th grade boys in Mandarin Chinese?

(A) 10
(B) 40
(C) 70
(D) 100
(E) 130

with all the corrections given above in the question...

210 Girls in 5th & 90 Boys in 5th do not take bla bla... = 5th grade is having mix of Girls and Boys

The number of 4th grade girls taking Mandarin Chinese is less than half bla bla..(less than half could be 0) +
all the students are boys or girls in the 4th or 5th grade +
question asked for number of boys in 4th grade (non zero ans option so) = 4th grade is having only Boys (320 Boys)

40% of the 4th graders take Mandarin Chinese + number of 4th grade boys in Mandarin Chinese = 320*(4/10) =128

please correct me...
Director
Director
User avatar
P
Joined: 05 Mar 2015
Posts: 962
Re: At Mnemosyne Middle School, there are 700 students: all the students a [#permalink]

Show Tags

New post 27 Apr 2017, 07:11
mikemcgarry wrote:
chetan2u wrote:
mikemcgarry wrote:
At Mnemosyne Middle School, there are 700 students: all the students are boys or girls in the 4th or 5th grade. There are 320 students in the 4th grade, and there are 210 girls in the 5th grade. Fifty percent of the 5th graders and 40% of the 4th graders take Mandarin Chinese. Ninety 5th grade boys do not take Mandarin Chinese. The number of 4th grade girls taking Mandarin Chinese is less than half of the number of 5th grade girls taking Mandarin Chinese. Which of the following could be the number of 5th grade boys in Mandarin Chinese?

(A) 10
(B) 40
(C) 70
(D) 100
(E) 130


This is one of a set of fifteen challenging GMAT Quant problems. To see the whole collection, as well as the OE for this question, go to:
Challenging GMAT Math Practice Questions

Mike :-)

Hi

A point..
Either the Q has some typo error or it contains unnecessary info and wrong choices

LeonidK wrote:
According to OA from Magoosh website - answer is about 4th grade boys taking Mandarin Chinese, not 5th...

Dear chetan2u & LeonidK,

Thank you very much to both of you! :-) Yes, these tiny typos sometimes are the hardest things to find and notice. Indeed, the prompt question was supposed to be about the number of 4th grade boys in Mandarin.

I corrected the question above and the blog. Thank you very much for finding this typo!

Mike McGarry :-)



mikemcgarry

Please make above question correct as said earlier :o
thanks
Senior CR Moderator
User avatar
V
Status: Long way to go!
Joined: 10 Oct 2016
Posts: 1335
Location: Viet Nam
GMAT ToolKit User Premium Member
Re: At Mnemosyne Middle School, there are 700 students: all the students a [#permalink]

Show Tags

New post 27 Apr 2017, 07:56
2
This post was
BOOKMARKED
The correct question written on blog as below.
mikemcgarry: Please make sure your question correct.

Quote:
At Mnemosyne Middle School, there are 700 students: all the students are boys or girls in the 4th or 5th grade. There are 320 students in the 4th grade, and there are 210 girls in the 5th grade. Fifty percent of the 5th graders and 40% of the 4th graders take Mandarin Chinese. Ninety 5th grade boys do not take Mandarin Chinese. The number of 4th grade girls taking Mandarin Chinese is less than half of the number of 5th grade girls taking Mandarin Chinese. Which of the following could be the number of 4th grade boys in Mandarin Chinese?

(A) 10
(B) 40
(C) 70
(D) 100
(E) 130


Here is the table I've made for easier view.
Attachment:
Table.PNG
Table.PNG [ 4.47 KiB | Viewed 1130 times ]


First, there are 320 4th grade students, so there are 700 - 320 = 380 students in 5th grade.

There are 210 girls in 5th grade so there are 380 - 210 = 170 boys in 5th grade.

50% of the 5th graders take MC, or 50% * 380 = 190 students in 5th grade take MC.

40% of the 4th graders take MC, or 40% * 320 = 128 students in 4th grade take MC.

90 boys in 5th grade don't take MC => the remaining 170 - 90 = 80 boys in 5th grade take MC.

Hence there are 190 - 80 = 110 girls in 5th grade take MC.

The number of 4th grade girls taking MC is less than 1/2 of the number of 5th grade girls taking MC. There are 110 girls in 5th grade take MC, so the number of 4th grade girls taking MC is less than 1/2 * 110 = 55

Note that there are 128 students in 4th grade taking MC, so the number of boys in 4th grade taking MC must greater than 128 - 55 = 73.

Now, A, B, C are out.

Note that there are 128 students in 4th grade taking MC, so the number of boys in 4th grade taking MC cannot greater than 128, so E is out.

The answer is D.
_________________

Actual LSAT CR bank by Broall

How to solve quadratic equations - Factor quadratic equations
Factor table with sign: The useful tool to solve polynomial inequalities
Applying AM-GM inequality into finding extreme/absolute value

New Error Log with Timer

Expert Post
Magoosh GMAT Instructor
User avatar
G
Joined: 28 Dec 2011
Posts: 4680
Re: At Mnemosyne Middle School, there are 700 students: all the students a [#permalink]

Show Tags

New post 27 Apr 2017, 11:02
rohit8865 wrote:
mikemcgarry

Please make above question correct as said earlier :o
thanks

Dear rohit8865

Done. :-)

Mike :-)
_________________

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)

Intern
Intern
User avatar
S
Status: I am not giving up. Not yet.
Joined: 23 Jul 2015
Posts: 47
GMAT ToolKit User Premium Member
Re: At Mnemosyne Middle School, there are 700 students: all the students a [#permalink]

Show Tags

New post 03 May 2017, 00:56
mikemcgarry wrote:
At Mnemosyne Middle School, there are 700 students: all the students are boys or girls in the 4th or 5th grade. There are 320 students in the 4th grade, and there are 210 girls in the 5th grade. Fifty percent of the 5th graders and 40% of the 4th graders take Mandarin Chinese. Ninety 5th grade boys do not take Mandarin Chinese. The number of 4th grade girls taking Mandarin Chinese is less than half of the number of 4th 5th grade girls taking Mandarin Chinese. Which of the following could be the number of 4th grade boys in Mandarin Chinese?

(A) 10
(B) 40
(C) 70
(D) 100
(E) 130


This is one of a set of fifteen challenging GMAT Quant problems. To see the whole collection, as well as the OE for this question, go to:
Challenging GMAT Math Practice Questions

Mike :-)


Wonderful question ruined by typos.
_________________

Cheers
PeeKay

Manager
Manager
avatar
S
Joined: 09 Mar 2017
Posts: 86
Location: Indonesia
Concentration: General Management, Finance
Schools: Erasmus '18 (A)
GMAT 1: 670 Q47 V36
GPA: 2.8
Re: At Mnemosyne Middle School, there are 700 students: all the students a [#permalink]

Show Tags

New post 03 May 2017, 01:35
No of students in 4th grade=320
No of students in 5th grade=380 (boys=170, girls=210)

Students taking Mandarin Chinese:
4th grade: 0.4*128=128 (boys=x, girls= less than 55 (half of girls in 5th grade)

5th grade: 0.5*380=190 (boys=80, girls=110)

A, B, C are crossed out because their sum will not reach 128
E is crossed out because it will exceed 130

D IMO


Sent from my SM-G935F using GMAT Club Forum mobile app
Expert Post
Magoosh GMAT Instructor
User avatar
G
Joined: 28 Dec 2011
Posts: 4680
Re: At Mnemosyne Middle School, there are 700 students: all the students a [#permalink]

Show Tags

New post 03 May 2017, 12:15
PKay wrote:
mikemcgarry wrote:
At Mnemosyne Middle School, there are 700 students: all the students are boys or girls in the 4th or 5th grade. There are 320 students in the 4th grade, and there are 210 girls in the 5th grade. Fifty percent of the 5th graders and 40% of the 4th graders take Mandarin Chinese. Ninety 5th grade boys do not take Mandarin Chinese. The number of 4th grade girls taking Mandarin Chinese is less than half of the number of 4th 5th grade girls taking Mandarin Chinese. Which of the following could be the number of 4th grade boys in Mandarin Chinese?

(A) 10
(B) 40
(C) 70
(D) 100
(E) 130


This is one of a set of fifteen challenging GMAT Quant problems. To see the whole collection, as well as the OE for this question, go to:
Challenging GMAT Math Practice Questions

Mike :-)


Wonderful question ruined by typos.

Dear PKay,

I corrected this in the entry at the top. Thanks for pointing this out.

Mike :-)
_________________

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)

Manager
Manager
avatar
B
Joined: 14 May 2015
Posts: 52
At Mnemosyne Middle School, there are 700 students: all the students a [#permalink]

Show Tags

New post 03 May 2017, 16:10
total student=700
4th student=320
5th student=380 [G=210 B=170]

Chinese:
5th student(B+G)=190
4th student(B+G)=128

5th student:
B not chn=90
B chn=170-90=80
G chn=190-80=110

4th G chn<(5th G chn)/2
4th G chn<110/2
4th G chn<55

if 4th G chn=54
then, 4th B chn=128-54=74

if 4th G chn=0
then, 4th B chn=128-0=128

74<= 4th B chn <=128

Only possible answer is D (100)
Manager
Manager
avatar
B
Joined: 19 Aug 2015
Posts: 119
Location: India
GMAT 1: 650 Q49 V30
Re: At Mnemosyne Middle School, there are 700 students: all the students a [#permalink]

Show Tags

New post 05 May 2017, 07:18
Given:
Total 700
4th grade 320
5th grade girls- 210
50% 5th grade and 40th % 4th grade takes MC
90 5th grade boys do not take MC
4th grade girls taking MC < half of 5th grade girls taking MC
Find 4th grade boys taking MC?
Analysis:
4th grade has 320 so 5th grade has 700-320=380
5th grade has 210 girls so number of boys = 380-210=170
Out of these 170 boys, 90 do not take MC so 80 take MC
Girls in 5th grade taking MC = (50% of 380) - 80=110
4th grade MC = 40% of320=128
Maximum girls taking MC in 4th grade should be atleast one less than half of 5th grade girls taking MC = 110/2-1=54
So number of 4th grade boys taking MC is atleast 128-54=74.
Answer D matches(100>74) as it can not be E(130>128)
Re: At Mnemosyne Middle School, there are 700 students: all the students a   [#permalink] 05 May 2017, 07:18
Display posts from previous: Sort by

At Mnemosyne Middle School, there are 700 students: all the students a

  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®.