GMAT Question of the Day - Daily to your Mailbox; hard ones only

It is currently 18 Jun 2019, 20:08

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

How many students in a room are currently taking either geography

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

Hide Tags

 
Manager
Manager
User avatar
P
Joined: 03 Mar 2018
Posts: 214
How many students in a room are currently taking either geography  [#permalink]

Show Tags

New post 03 Jan 2019, 07:51
00:00
A
B
C
D
E

Difficulty:

  15% (low)

Question Stats:

85% (01:02) correct 15% (01:12) wrong based on 52 sessions

HideShow timer Statistics

How many students in a room are currently taking either geography or history, but not both?

(1) The number of students in the room who are taking at least one of the subjects history and geography is 127.
(2) The number of students in the room who are taking both geography and history is 46.

_________________
Please mention my name in your valuable replies.
Senior Manager
Senior Manager
User avatar
P
Joined: 17 Oct 2016
Posts: 259
Location: India
Concentration: General Management, Healthcare
GMAT 1: 640 Q40 V38
GMAT 2: 680 Q48 V35
GPA: 3.05
WE: Pharmaceuticals (Health Care)
Reviews Badge CAT Tests
Re: How many students in a room are currently taking either geography  [#permalink]

Show Tags

New post 03 Jan 2019, 08:08
1
itisSheldon wrote:
How many students in a room are currently taking either geography or history, but not both?

(1) The number of students in the room who are taking at least one of the subjects history and geography is 127.
(2) The number of students in the room who are taking both geography and history is 46.


The formula I use is
Total = Group A + Group B - Both Group + Neither Group

We want to know Group A + Group B

A: The number of students in the room who are taking at least one of the subjects history and geography is 127:

So Total = 127 AND Neither = 0. But we dont know Both Group : NOT SUFFICIENT

B: The number of students in the room who are taking both geography and history is 46.

So Both Group = 46. But Total and Neither Group is unknown. : NOT SUFFICIENT

BOTH A and B TOGETHER. WE Know the values.: SUFFICIENT
_________________
_____________________
Chasing the dragon
GMAT Tutor
User avatar
B
Joined: 07 Nov 2016
Posts: 56
GMAT 1: 760 Q51 V42
Premium Member
Re: How many students in a room are currently taking either geography  [#permalink]

Show Tags

New post 03 Jan 2019, 22:51
itisSheldon wrote:
How many students in a room are currently taking either geography or history, but not both?

(1) The number of students in the room who are taking at least one of the subjects history and geography is 127.
(2) The number of students in the room who are taking both geography and history is 46.


Let H be the number of students taking History

Let G be the number of students taking Geography

Let x be the number of students taking both History and Geography

H-x = History alone

G-x = Geography alone

So, Either Geography or History but not both = H-x +G-x = H + G - 2x = ?

St 1 : H + G - x =127

Not Sufficient

St 2 :

x = 46

Not Sufficient

St 1 and St 2 Combined

H + G- 2x = (H + G - x) - x

= 127 - 46 = 81

Sufficient

Choice C
_________________
Please contact me at ksrutisagar@gmail.com
Director
Director
User avatar
S
Status: Come! Fall in Love with Learning!
Joined: 05 Jan 2017
Posts: 542
Location: India
Re: How many students in a room are currently taking either geography  [#permalink]

Show Tags

New post 03 Jan 2019, 23:51
Hi,

It’s a pretty-straight forward sets question.

You can use venn-diagrams to solve the sets questions.

Question: How many students chose exactly one of the subject (i.e., history or geography) ?

Statement I is insufficient:

The number of students in the room who are taking at least one of the subjects history and geography is 127.

Given, no. of students who took atleast one of the subjects is equal to 127.

But we want students who chosen exactly one subject.

From the below diagram,

We can see that, if we know the number of students who chosed both, we can find the answer.

Statement II is insufficient:

The number of students in the room who are taking both geography and history is 46.

Now we can clearly see that, statement II individually not sufficient.

But combining both I and II, we will get the answer.

That is, 127 – 46 = 81.

So the answer is C.

Hope this helps.

Regards,
Junaid.
Byjus GMAT Quant Expert
Attachments

GMATClub Sets - o4-01-19.png
GMATClub Sets - o4-01-19.png [ 50.43 KiB | Viewed 457 times ]


_________________
GMAT Mentors
Image
Intern
Intern
avatar
B
Joined: 16 Jul 2018
Posts: 38
GMAT ToolKit User Premium Member CAT Tests
Re: How many students in a room are currently taking either geography  [#permalink]

Show Tags

New post 10 Jan 2019, 06:46
fitzpratik wrote:
itisSheldon wrote:
How many students in a room are currently taking either geography or history, but not both?

(1) The number of students in the room who are taking at least one of the subjects history and geography is 127.
(2) The number of students in the room who are taking both geography and history is 46.


The formula I use is
Total = Group A + Group B - Both Group + Neither Group

We want to know Group A + Group B

A: The number of students in the room who are taking at least one of the subjects history and geography is 127:

So Total = 127 AND Neither = 0. But we dont know Both Group : NOT SUFFICIENT

B: The number of students in the room who are taking both geography and history is 46.

So Both Group = 46. But Total and Neither Group is unknown. : NOT SUFFICIENT

BOTH A and B TOGETHER. WE Know the values.: SUFFICIENT


Hi fitzpratik ,

So if the stem is not referring about Neither subgroup we just assume that it is 0 or u realized it from somewhere else?
Senior Manager
Senior Manager
User avatar
P
Joined: 17 Oct 2016
Posts: 259
Location: India
Concentration: General Management, Healthcare
GMAT 1: 640 Q40 V38
GMAT 2: 680 Q48 V35
GPA: 3.05
WE: Pharmaceuticals (Health Care)
Reviews Badge CAT Tests
Re: How many students in a room are currently taking either geography  [#permalink]

Show Tags

New post 10 Jan 2019, 07:05
1
UNSTOPPABLE12 wrote:
fitzpratik wrote:
itisSheldon wrote:
How many students in a room are currently taking either geography or history, but not both?

(1) The number of students in the room who are taking at least one of the subjects history and geography is 127.
(2) The number of students in the room who are taking both geography and history is 46.


The formula I use is
Total = Group A + Group B - Both Group + Neither Group

We want to know Group A + Group B

A: The number of students in the room who are taking at least one of the subjects history and geography is 127:

So Total = 127 AND Neither = 0. But we dont know Both Group : NOT SUFFICIENT

B: The number of students in the room who are taking both geography and history is 46.

So Both Group = 46. But Total and Neither Group is unknown. : NOT SUFFICIENT

BOTH A and B TOGETHER. WE Know the values.: SUFFICIENT


Hi fitzpratik ,

So if the stem is not referring about Neither subgroup we just assume that it is 0 or u realized it from somewhere else?


The question stem usually mentions that students are taking EITHER geography or history, we cannot assume they are giving any other exam.

If the question stem would have been :

Students are taking either geography or history, among other subjects, ....then our assumption of Neither = 0 might not be true.
_________________
_____________________
Chasing the dragon
Manager
Manager
avatar
S
Joined: 16 Oct 2011
Posts: 94
GMAT 1: 620 Q37 V38
GMAT 2: 640 Q36 V41
GMAT 3: 650 Q42 V38
GMAT 4: 650 Q44 V36
GMAT 5: 570 Q31 V38
How many students in a room are currently taking either geography  [#permalink]

Show Tags

New post 10 Jan 2019, 07:53
itisSheldon wrote:
How many students in a room are currently taking either geography or history, but not both?

(1) The number of students in the room who are taking at least one of the subjects history and geography is 127.
(2) The number of students in the room who are taking both geography and history is 46.



To make this problem work, we have to assume that all students are taking at least one class, otherwise we have too many unknown. Venn Diagrams are great, as they can allow us to use the NVNE sufficiency strategy for DS, however for two overlapping set problems, I prefer to use a 2x2 table.

(1) We can construct the following table the first table. The cells labelled X and Y represent the total students taking only history or only geography. With (1) we still don't know how many are in both geography and history so NS

(2) We can construct the second table. We don't know the total number of students, so (2) is clearly NS

(1) and (2) We can construct the third table. Since we know have the total and the number of students taking both classes, we can determine the remaining 2 cells in the center of the table, X+Y, which is exactly what we are looking for. Sufficient. The answer is C
Attachments

Capture2.PNG
Capture2.PNG [ 1.64 KiB | Viewed 321 times ]

Capture1.PNG
Capture1.PNG [ 1.36 KiB | Viewed 320 times ]

Capture.PNG
Capture.PNG [ 1.48 KiB | Viewed 320 times ]

GMAT Club Bot
How many students in a room are currently taking either geography   [#permalink] 10 Jan 2019, 07:53
Display posts from previous: Sort by

How many students in a room are currently taking either geography

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


Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne