Find all School-related info fast with the new School-Specific MBA Forum

 It is currently 27 Jul 2016, 06:53

### 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

# At a certain university, the ratio of the number of teaching

Author Message
TAGS:

### Hide Tags

Intern
Joined: 28 Jun 2008
Posts: 46
Followers: 0

Kudos [?]: 48 [1] , given: 31

At a certain university, the ratio of the number of teaching [#permalink]

### Show Tags

04 Jun 2009, 21:11
1
KUDOS
10
This post was
BOOKMARKED
00:00

Difficulty:

45% (medium)

Question Stats:

62% (01:54) correct 38% (01:03) wrong based on 470 sessions

### HideShow timer Statistics

At a certain university, the ratio of the number of teaching assistants to the number of students in any course must always be greater than 3:80. At this university , what is the maximum number of students possible in a course that has 5 teaching assistants?

A. 130
B. 131
C. 132
D. 133
E. 134
[Reveal] Spoiler: OA

Last edited by Bunuel on 13 Mar 2012, 00:35, edited 1 time in total.
Edited the question and added the OA
Manager
Joined: 12 Apr 2006
Posts: 218
Location: India
Followers: 1

Kudos [?]: 25 [1] , given: 17

Re: problem solving question on ratios [#permalink]

### Show Tags

05 Jun 2009, 01:46
1
KUDOS
Not sure whether this is the best possible way but just the way how I solve it.

Teaching Assistants = TA
Students = S

Let assume the ratio of TA/S = $$3/80$$ (Just putting aside the requirement it must be greater)

Let say x be the maximum no of students possible with 5 teaching assistants = $$3/80 = 5/x$$

$$x = 400/3 = 133.33$$. Now for ratio to be greater than $$3/80$$ reduce the denominator. So just rounded it to lowest integer as number of student can't be in decimal. The new ratio is $$5/133$$, which is less than $$3/80$$ thus, 133 is the maximum number of students possible.
Director
Joined: 25 Oct 2008
Posts: 607
Location: Kolkata,India
Followers: 11

Kudos [?]: 621 [1] , given: 100

Re: problem solving question on ratios [#permalink]

### Show Tags

17 Jul 2009, 19:34
1
KUDOS
$$\frac{TA}{S} > \frac{3}{80}$$

$$\frac{5}{x} > \frac{3}{80}$$

400 > 3x where x has to be maximum.

Substituting the values, if x= 133, 3x=399.

hence,D:)
_________________

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

Manager
Joined: 11 Sep 2009
Posts: 109
Followers: 2

Kudos [?]: 23 [0], given: 0

Re: problem solving question on ratios [#permalink]

### Show Tags

24 Oct 2009, 00:29
TA : S > 3 : 80

5 : S > 3 : 80

S < 400 / 3 = 133 (MAX)
Manager
Joined: 05 Nov 2010
Posts: 63
Followers: 1

Kudos [?]: 1 [0], given: 5

Re: problem solving question on ratios [#permalink]

### Show Tags

16 Dec 2010, 14:36
can someone explain in further detail the relationship between the teaching assistants to the number of students in any course must always be greater than 3:80 and how to reason through this portion? I understand how to solve for x. Once I was at this point I think was stumped on which number to select and inevitably chose to round up. My rational being .33 of a student is not possible therefore it must represent the position of an entire student. Thoughts? Help?
Math Expert
Joined: 02 Sep 2009
Posts: 34090
Followers: 6091

Kudos [?]: 76623 [5] , given: 9977

Re: problem solving question on ratios [#permalink]

### Show Tags

16 Dec 2010, 14:47
5
KUDOS
Expert's post
3
This post was
BOOKMARKED
spyguy wrote:
can someone explain in further detail the relationship between the teaching assistants to the number of students in any course must always be greater than 3:80 and how to reason through this portion? I understand how to solve for x. Once I was at this point I think was stumped on which number to select and inevitably chose to round up. My rational being .33 of a student is not possible therefore it must represent the position of an entire student. Thoughts? Help?

At a certain university, the ratio of the number of teaching assistants to the number of students in any course must always be greater than 3:80. At this university, what is the maximum number of students possible in a course that has 5 teaching assistants?
A. 130
B. 131
C. 132
D. 133
E. 134

Given: $$\frac{assistants}{students}>\frac{3}{80}$$ --> $$assistants=5$$, so $$\frac{5}{s}>\frac{3}{80}$$ --> $$s_{max}=?$$

$$\frac{5}{s}>\frac{3}{80}$$ --> $$s<\frac{5*80}{3}\approx{133.3}$$ --> so $$s_{max}=133$$.

$$\frac{assistants}{students}>\frac{3}{80}$$ relationship means that if for example # of assistants is 3 then in order $$\frac{assistants}{students}>\frac{3}{80}$$ to be true then # of students must be less than 80 (so there must be less than 80 students per 3 assistants) on the other hand if # of students is for example 80 then the # of assistants must be more than 3 (so there must be more than 3 assistants per 80 students).

Hope it's clear.
_________________
Manager
Joined: 05 Nov 2010
Posts: 63
Followers: 1

Kudos [?]: 1 [0], given: 5

Re: problem solving question on ratios [#permalink]

### Show Tags

16 Dec 2010, 14:57
Bunuel,

That is very clear. Thanks for breaking it down like that as it is more clear in order to solve future problems.
Manager
Joined: 23 Feb 2012
Posts: 216
Location: India
Concentration: Finance, Entrepreneurship
Schools: Said
GMAT 1: 710 Q44 V44
GPA: 2.9
WE: Marketing (Computer Software)
Followers: 5

Kudos [?]: 46 [0], given: 22

### Show Tags

12 Mar 2012, 22:45
At a certain restaurant, the ratio of the number of chefs to the number of burgers on any day must always be greater than 3:80. At this restaurant, what is the maximum number of burgers possible on a day that has 5 chefs.

A) 130
B) 131
C) 132
D) 133
E) 134

[EDIT] The same problem has been solved elsewhere:
problem-solving-question-on-ratios-79240.html

Sorry, I couldn't delete this post!
_________________

If you like it, Kudo it!

"There is no alternative to hard work. If you don't do it now, you'll probably have to do it later. If you didn't need it now, you probably did it earlier. But there is no escaping it."

710 Debrief. Crash and Burn

Last edited by budablasta on 12 Mar 2012, 23:50, edited 1 time in total.
Senior Manager
Status: May The Force Be With Me (D-DAY 15 May 2012)
Joined: 06 Jan 2012
Posts: 289
Location: India
Concentration: General Management, Entrepreneurship
Followers: 2

Kudos [?]: 206 [1] , given: 16

### Show Tags

12 Mar 2012, 23:42
1
KUDOS
hi,

I solved it this way, any suggestions always welcome

c/b > 3/80 ( from question)

5/b > 3 / 80
(80 x 5 / 3) > b

This reduces to

133.3333 > b

So the number of burgers have to be less than 133.33 & as u dont get 0.33 burger in Mc Donalds Max burgers is 133

Give me a Big Kudoos Meal Combo if this helps
_________________

Giving +1 kudos is a better way of saying 'Thank You'.

Last edited by boomtangboy on 12 Mar 2012, 23:55, edited 1 time in total.
Manager
Joined: 23 Feb 2012
Posts: 216
Location: India
Concentration: Finance, Entrepreneurship
Schools: Said
GMAT 1: 710 Q44 V44
GPA: 2.9
WE: Marketing (Computer Software)
Followers: 5

Kudos [?]: 46 [0], given: 22

### Show Tags

12 Mar 2012, 23:49
boomtangboy wrote:
hi,

Give me a Big Kudoos Meal Combo if this helps

_________________

If you like it, Kudo it!

"There is no alternative to hard work. If you don't do it now, you'll probably have to do it later. If you didn't need it now, you probably did it earlier. But there is no escaping it."

710 Debrief. Crash and Burn

Senior Manager
Status: May The Force Be With Me (D-DAY 15 May 2012)
Joined: 06 Jan 2012
Posts: 289
Location: India
Concentration: General Management, Entrepreneurship
Followers: 2

Kudos [?]: 206 [0], given: 16

### Show Tags

13 Mar 2012, 00:10
budablasta wrote:
boomtangboy wrote:
hi,

Give me a Big Kudoos Meal Combo if this helps

Happy to Help
_________________

Giving +1 kudos is a better way of saying 'Thank You'.

Math Expert
Joined: 02 Sep 2009
Posts: 34090
Followers: 6091

Kudos [?]: 76623 [0], given: 9977

### Show Tags

13 Mar 2012, 00:40
Expert's post
budablasta wrote:
At a certain restaurant, the ratio of the number of chefs to the number of burgers on any day must always be greater than 3:80. At this restaurant, what is the maximum number of burgers possible on a day that has 5 chefs.

A) 130
B) 131
C) 132
D) 133
E) 134

[EDIT] The same problem has been solved elsewhere:
problem-solving-question-on-ratios-79240.html

Sorry, I couldn't delete this post!

Merging similar topics.
_________________
GMAT Club Legend
Joined: 09 Sep 2013
Posts: 10612
Followers: 495

Kudos [?]: 129 [0], given: 0

Re: At a certain university, the ratio of the number of teaching [#permalink]

### Show Tags

05 Apr 2015, 06:25
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.
_________________
Manager
Joined: 11 Nov 2014
Posts: 230
Location: India
WE: Project Management (Telecommunications)
Followers: 0

Kudos [?]: 20 [0], given: 6

Re: At a certain university, the ratio of the number of teaching [#permalink]

### Show Tags

26 Jan 2016, 10:18
budablasta wrote:
At a certain restaurant, the ratio of the number of chefs to the number of burgers on any day must always be greater than 3:80. At this restaurant, what is the maximum number of burgers possible on a day that has 5 chefs.

A) 130
B) 131
C) 132
D) 133
E) 134

[EDIT] The same problem has been solved elsewhere:
problem-solving-question-on-ratios-79240.html

Sorry, I couldn't delete this post!

same for me
Please help. The phrase "must always be greater than" states it has to be 134 & not 133
what is the catch here?

I thought I was good at ratios!
Manager
Joined: 09 Jul 2013
Posts: 109
GMAT 1: 750 Q V
GMAT 2: 760 Q V
Followers: 2

Kudos [?]: 51 [1] , given: 6

Re: At a certain university, the ratio of the number of teaching [#permalink]

### Show Tags

26 Jan 2016, 14:53
1
KUDOS
The question states that the ratio must always be greater than 3:80, not the number of students (or burgers). So when you calculate the ratio $$\frac{5}{x}>\frac{3}{80}$$, increasing the value of $$x$$ will decrease the ratio $$\frac{5}{x}$$, and decreasing the value of $$x$$ will increase the ratio $$\frac{5}{x}$$.

If you calculate the number of burgers to be 133.3, then decide whether to round up or down, understand what will happen to the ratio of $$\frac{5}{x}$$.

If $$\frac{5}{133.33}=\frac{3}{80}$$, and that is the minimum (because $$\frac{5}{x}$$ must always be greater than $$\frac{3}{80}$$), what happens if you round $$x$$ up to 134? Is $$\frac{5}{134}$$ > or < $$\frac{3}{80}$$?

As explained above, if you increase $$x$$ to 134, then the ratio $$\frac{5}{x}$$ is decreased, and it will be less than the minimum of $$\frac{3}{80}$$. If you round $$x$$ down to 133, then the ratio $$\frac{5}{x}$$ will increase, and you will not violate the condition that it must always be greater than $$\frac{3}{80}$$.

Looking at it another way, if we know that the ratio of assistants to students must always be greater than 3:80, then we know that for any given number of assistants, there is a maximum number of students allowed. For every assistant, a maximum of 26.66 students are allowed (80/3). So if there is 1 assistant and 27 students, that is too many. 26 is the maximum number of students allowed if there is only 1 assistant in order to keep the ratio greater than 3:80. Using the same logic, if there are 5 assistants, then the maximum number of students allowed is 133.33. If there were 134 students that would be more than the maximum, therefore the maximum number of students allowed is 133.

Does that help?

Cheers
_________________

Dave de Koos

Manager
Joined: 11 Nov 2014
Posts: 230
Location: India
WE: Project Management (Telecommunications)
Followers: 0

Kudos [?]: 20 [0], given: 6

Re: At a certain university, the ratio of the number of teaching [#permalink]

### Show Tags

27 Jan 2016, 06:29
Yes, davedekoos
understand what will happen to the ratio that solved it 50%
VP
Joined: 08 Jul 2010
Posts: 1201
Location: India
GMAT: INSIGHT
WE: Education (Education)
Followers: 46

Kudos [?]: 1052 [0], given: 40

Re: At a certain university, the ratio of the number of teaching [#permalink]

### Show Tags

27 Jan 2016, 06:59
Expert's post
scorpio7 wrote:
At a certain university, the ratio of the number of teaching assistants to the number of students in any course must always be greater than 3:80. At this university , what is the maximum number of students possible in a course that has 5 teaching assistants?

A. 130
B. 131
C. 132
D. 133
E. 134

$$\frac{Assistant}{Student} > \frac{3}{80}$$

$$\frac{5}{Student} > \frac{3}{80}$$

$$Student < \frac{(5*80)}{3}$$

$$Student < \frac{(400)}{3}$$

i.e. $$Student < 133.33$$

i.e. Maximum value of No. of students = 133

_________________

Prosper!!!

GMATinsight

Bhoopendra Singh and Dr.Sushma Jha
e-mail: info@GMATinsight.com
Call us : +91-9999687183 / 9891333772
http://www.GMATinsight.com/testimonials.html

Contact for One-on-One LIVE ONLINE (SKYPE Based) or CLASSROOM Quant/Verbal FREE Demo Class

GMATinsight
107, 1st Floor, Krishna Mall, Sector-12 (Main market), Dwarka, New Delhi-110075

______________________________________________________
Please press the if you appreciate this post !!

Verbal Forum Moderator
Joined: 15 Apr 2013
Posts: 194
Location: India
Concentration: General Management, Marketing
GMAT Date: 11-23-2015
GPA: 3.6
WE: Science (Other)
Followers: 14

Kudos [?]: 362 [0], given: 28

At a certain university, the ratio of the number of teaching [#permalink]

### Show Tags

25 Feb 2016, 12:56
Brute Force Method:

$$\frac{3}{80}$$ As we are looking to a similar ratio for 5 assistants instead of 3, convert the both numerator (3) and denominator (80) to multiple of 5 by multiplying with 5

$$\frac{3*5}{80*5}$$equivalent to

$$\frac{15}{400}$$

Now as we need ratio for 05 assistants; again divide both numerator and denominator with 3. Pay attention to denominator which we need to answer:

$$\frac{5}{133.33}$$ (Post division of both numerator and denominator with 03)

DONE

Maximum students could be 133 because if students 134 ratio would be less.

Hope it helps!!!!
At a certain university, the ratio of the number of teaching   [#permalink] 25 Feb 2016, 12:56
Similar topics Replies Last post
Similar
Topics:
In a certain company, the ratio of the number of managers to the 2 25 Jul 2016, 17:10
34 In a certain district, the ratio of the number of registered 20 12 Dec 2012, 04:38
At a certain university, the ratio of the number of teaching assistant 4 17 Mar 2011, 19:38
11 At a certain university, the ratio of the number of teaching 7 24 Oct 2010, 17:57
29 At a Certain school, the ratio of the number of second 17 16 Jul 2009, 11:59
Display posts from previous: Sort by