Summer is Coming! Join the Game of Timers Competition to Win Epic Prizes. Registration is Open. Game starts Mon July 1st.

It is currently 18 Jul 2019, 23:05

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

There are 42 students in a group. If each student is either

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

Hide Tags

Find Similar Topics 
Senior Manager
Senior Manager
User avatar
Joined: 25 Oct 2008
Posts: 492
Location: Kolkata,India
There are 42 students in a group. If each student is either  [#permalink]

Show Tags

New post Updated on: 22 Apr 2014, 02:29
1
7
00:00
A
B
C
D
E

Difficulty:

  55% (hard)

Question Stats:

61% (01:52) correct 39% (01:49) wrong based on 186 sessions

HideShow timer Statistics


There are 42 students in a group. If each student is either a freshmen or a senior, how many of the students are seniors?

(1) The group has more than four times as many seniors as it has freshmen.

(2) The group has more than 7 freshmen.

_________________
http://gmatclub.com/forum/countdown-beginshas-ended-85483-40.html#p649902

Originally posted by tejal777 on 29 Sep 2009, 19:07.
Last edited by Bunuel on 22 Apr 2014, 02:29, edited 1 time in total.
Edited the question and added the OA.
Manager
Manager
User avatar
Joined: 21 May 2009
Posts: 86
Re: freshmen or a senior  [#permalink]

Show Tags

New post 29 Sep 2009, 19:14
1
There are 42 students in a group. If each student is either a freshmen or a senior, how many of the students are seniors?

(1) The group has more than four times as many seniors as it has freshmen.

(2) The group has more than 7 freshmen.


from 1:

the total sudents would be f*5 + x=42

from 2:
Substituting a value more than 7(only 8 satisfies)
will give a solution

SO C is the Answer
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 56260
Re: F + S  [#permalink]

Show Tags

New post 25 Oct 2009, 16:53
2
1
There are 42 students in a group. If each student is either a freshmen or a senior, how many of the students are seniors?

Given: S+F=42.
Question: S=?

(1) The group has more than four times as many seniors as it has freshmen --> \(S>4F\) --> \(S>4*(42-S)\) --> \(S>33.6\). The number of seniors can be 34, 35, ... Not sufficient.

(2) The group has more than 7 freshmen --> \(F>7\) --> \(42-S>7\) --> \(S<35\). Not sufficient.

(1)+(2) \(S>33.6\) and \(S<35\) --> \(S=34\). Sufficient.

Answer: C.
_________________
Manager
Manager
User avatar
Affiliations: PMP
Joined: 13 Oct 2009
Posts: 242
Re: F + S  [#permalink]

Show Tags

New post 25 Oct 2009, 19:52
I got C too. solution F=8 and S=34 is the only possibility from S1 and S2
_________________
Thanks, Sri
-------------------------------
keep uppp...ing the tempo...

Press +1 Kudos, if you think my post gave u a tiny tip
Manager
Manager
User avatar
Joined: 26 Jul 2010
Posts: 75
Location: India
Concentration: Operations, General Management
Schools: IIMA (M)
GMAT 1: 640 Q48 V29
GMAT 2: 670 Q49 V31
WE: Supply Chain Management (Military & Defense)
Re: freshmen or a senior  [#permalink]

Show Tags

New post 23 Apr 2011, 03:23
ST 1 - insufficent
st 2 - in suff
combing 1 & 2
we get only one value > 7 which is 8 that satisfy answer

hence c
_________________
lets start again
Director
Director
avatar
Joined: 01 Feb 2011
Posts: 629
Re: freshmen or a senior  [#permalink]

Show Tags

New post 23 Apr 2011, 07:38
f + s =42.

1. Insufficient
s > 4f
s > 4(42-s)
s > 33.6
s >=34
s could be 34 ,35....

2. Insufficient.

we dont know anthing about s.

together , Sufficient
as s = 34 , f = 8 is the only combination that satisfies 1 and 2.

Answer is C.
Manager
Manager
avatar
Joined: 11 Dec 2010
Posts: 106
WE: Consulting (Consulting)
Re: freshmen or a senior  [#permalink]

Show Tags

New post 23 Apr 2011, 07:52
Statement 1 - Insufficient... Many answers are possible
Statement 2 - Nothing can be derived from this

Both together - 35 & 7 is an option but from statement 2, more than 7
34 and 8 is possible (more than 4:1 and also 8)
33 and 9 is not possible as statement 1 is not satisfied

So only one answer when two statements considered together


Answer C
Retired Moderator
avatar
B
Joined: 16 Nov 2010
Posts: 1358
Location: United States (IN)
Concentration: Strategy, Technology
Reviews Badge
Re: freshmen or a senior  [#permalink]

Show Tags

New post 23 Apr 2011, 09:33
x + y = 42

(1)

x > 4y


42 -y > 4y

y < 8.4

So, y = 8,7 etc.

x = 34, 35 etc.

Not Sufficient

(2)

y > 7

Not Sufficient

(1) and (2)

y = 8, x = 34

Answer - C
_________________
Formula of Life -> Achievement/Potential = k * Happiness (where k is a constant)

GMAT Club Premium Membership - big benefits and savings
Manager
Manager
User avatar
Joined: 10 Mar 2013
Posts: 184
GMAT 1: 620 Q44 V31
GMAT 2: 690 Q47 V37
GMAT 3: 610 Q47 V28
GMAT 4: 700 Q50 V34
GMAT 5: 700 Q49 V36
GMAT 6: 690 Q48 V35
GMAT 7: 750 Q49 V42
GMAT 8: 730 Q50 V39
Re: There are 42 students in a group. If each student is either  [#permalink]

Show Tags

New post 03 Dec 2013, 22:22
The translation of (1) killed me in this problem.
I thought it meant 4s > f. Can someone help me translate it to s > 4f?
Intern
Intern
avatar
Joined: 11 Nov 2013
Posts: 15
GMAT Date: 12-26-2013
GPA: 3.6
WE: Consulting (Computer Software)
Re: There are 42 students in a group. If each student is either  [#permalink]

Show Tags

New post 04 Dec 2013, 01:15
1
TooLong150 wrote:
The translation of (1) killed me in this problem.
I thought it meant 4s > f. Can someone help me translate it to s > 4f?



The statement clearly states that "more than four times as many seniors as it has freshmen."
Lets forget more than part here and focus on four times as many seniors as it has freshmen.
This means S=4F
now more than part . incorporate > in place of =.
So S > 4F
Intern
Intern
avatar
Joined: 11 Nov 2013
Posts: 15
GMAT Date: 12-26-2013
GPA: 3.6
WE: Consulting (Computer Software)
Re: There are 42 students in a group. If each student is either  [#permalink]

Show Tags

New post 04 Dec 2013, 01:22
C.

Statement 1:
s>4F

>4F+F = 42
F & S should be an integers.
So I found factors of 42 fitting to solve the equation .
Factors of 42 = 1,2,3,6,7,14,21,42.
So 5F + F = 42 => F=7 & S = 35
6F+F= 42 => F = 6 & S=36. and so on for other values. => Not sufficient.

Statement 2:
F>7.
Many values satisfy this condition such as F = 8 & S = 34; F=9 & S = 33 & so on =>Insufficient

Combine both :
F>7 and S>4F . F = 8 & S = 34

Hence C
Math Revolution GMAT Instructor
User avatar
V
Joined: 16 Aug 2015
Posts: 7605
GMAT 1: 760 Q51 V42
GPA: 3.82
Re: There are 42 students in a group. If each student is either  [#permalink]

Show Tags

New post 26 Jan 2016, 22:42
Forget conventional ways of solving math questions. In DS, Variable approach is the easiest and quickest way to find the answer without actually solving the problem. Remember equal number of variables and independent equations ensures a solution.

There are 42 students in a group. If each student is either a freshmen or a senior, how many of the students are seniors?

(1) The group has more than four times as many seniors as it has freshmen.

(2) The group has more than 7 freshmen.


In the original condition, there are 2 variables(f,s) and 1 equation(f+s=42), which should match with the number of equations. So you need 1 equation. For 1) 1 equation, for 2) 1 equation, which is likely to make D the answer.
For 1), in s>4f, value of s is not unique and not sufficient.
For 2), in f>7, value of s is also not unique and not sufficient. When 1) & 2), they become s>4f and f>7 → s+f>4f+7, 42>4f+7, 35>4f → 35/4=8.75>f. Since f>7, in 8.75>f>7, f=8, s=34, which is unique and sufficient.
Therefore, the answer is C.


--> For cases where we need 1 more equation, such as original conditions with “1 variable”, or “2 variables and 1 equation”, or “3 variables and 2 equations”, we have 1 equation each in both 1) and 2). Therefore, there is 59 % chance that D is the answer, while A or B has 38% chance and C or E has 3% chance. Since D is most likely to be the answer using 1) and 2) separately according to DS definition. Obviously there may be cases where the answer is A, B, C or E.
_________________
MathRevolution: Finish GMAT Quant Section with 10 minutes to spare
The one-and-only World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy.
"Only $79 for 1 month Online Course"
"Free Resources-30 day online access & Diagnostic Test"
"Unlimited Access to over 120 free video lessons - try it yourself"
Non-Human User
User avatar
Joined: 09 Sep 2013
Posts: 11704
Re: There are 42 students in a group. If each student is either  [#permalink]

Show Tags

New post 23 Dec 2018, 12:23
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 Club Bot
Re: There are 42 students in a group. If each student is either   [#permalink] 23 Dec 2018, 12:23
Display posts from previous: Sort by

There are 42 students in a group. If each student is either

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





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