Last visit was: 25 Apr 2024, 15:21 It is currently 25 Apr 2024, 15:21

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
SORT BY:
Kudos
Tags:
Show Tags
Hide Tags
User avatar
Intern
Intern
Joined: 19 Dec 2007
Posts: 39
Own Kudos [?]: 79 [19]
Given Kudos: 0
Send PM
Most Helpful Reply
SVP
SVP
Joined: 17 Nov 2007
Posts: 2408
Own Kudos [?]: 10036 [6]
Given Kudos: 361
Concentration: Entrepreneurship, Other
Schools: Chicago (Booth) - Class of 2011
GMAT 1: 750 Q50 V40
Send PM
General Discussion
User avatar
Veritas Prep GMAT Instructor
Joined: 11 Dec 2012
Posts: 310
Own Kudos [?]: 633 [3]
Given Kudos: 66
Send PM
avatar
Director
Director
Joined: 28 Dec 2005
Posts: 697
Own Kudos [?]: 535 [1]
Given Kudos: 2
Send PM
Re: PS: Please, advise on how to calculate quicker!!! [#permalink]
1
Kudos
i agree, i cant see a 'fast' way.

first step is to figure out how many total teachers there are, which is possible as you know the average salary and total salary

average = sum/total --> 26,000 = 3,380,000 / total --> total =130

students/teachers = 11/1 --> 11/1 = x/130 where x=# of students --> x=130*11
User avatar
Senior Manager
Senior Manager
Joined: 01 May 2007
Posts: 484
Own Kudos [?]: 1454 [0]
Given Kudos: 0
Send PM
Re: PS: Please, advise on how to calculate quicker!!! [#permalink]
Agree.. Just need to sharpen your basic math skills. Dividing 3380000/26000 should actually calculate out pretty fast when you cancel out some zeros.
User avatar
VP
VP
Joined: 29 Mar 2007
Posts: 1150
Own Kudos [?]: 1737 [0]
Given Kudos: 0
Send PM
Re: PS: Please, advise on how to calculate quicker!!! [#permalink]
I agree as well. Just gunna have to do some calculations.

3380000/26000 --> 130 then just 130*11 =1430.
User avatar
VP
VP
Joined: 29 Aug 2007
Posts: 1021
Own Kudos [?]: 1726 [0]
Given Kudos: 19
Send PM
Re: PS: Please, advise on how to calculate quicker!!! [#permalink]
chica wrote:
A certain college has a student-to-teacher ratio of 11 to 1. The average (arithmetic mean) annual salary for teachers is $26,000. If the college pays a total of $3,380,000 in annual salaries to its teachers, how many students does the college have ?
(A) 130
(B) 169
(C) 1,300
(D) 1,430
(E) 1,560


Hi, this is a pretty easy question, I know. Still, It took me a bit more than 3 min to perform all the calculation.. :oops: Are there any tips on how to calculate everything quicker? In general, I will greatly appreciate if anyone can share any ideas on how to do calculations quickly.. Calculations of fractions-decimals or just large numbers take my time. moreover I just tend to make careless mistakes here being pressed on time.......Please, advise..

Thanks much


no . of student = (11) ($3,380,000 / $26,000) = 11 (3380 / 26) = 11 (1649 / 13) = 11 (130) = 1,430

reducing numerator and denomenator would be sometime easy.
User avatar
Intern
Intern
Joined: 06 Feb 2013
Posts: 35
Own Kudos [?]: 206 [0]
Given Kudos: 35
Send PM
Re: PS: Please, advise on how to calculate quicker!!! [#permalink]
Could someone show me a purely algebraic approach. I can't connect those elements (two equations). I solve fast via the common sense, but I it looks like I am doing something silly on the proportions side.

I have this ready, after taking out three 0's, \(26t = 3800\) (after 3800/t=26), and then since we have \(11t=s\) it must be that \(\frac{s}{11}=\frac{t}{1}\)? But then, if it is true, I am confused with my common sense...please help me untangle myself. How do you express ratios as stated in the problem?
User avatar
Manager
Manager
Joined: 04 Apr 2013
Posts: 96
Own Kudos [?]: 176 [0]
Given Kudos: 36
Send PM
Re: PS: Please, advise on how to calculate quicker!!! [#permalink]
obs23 wrote:
Could someone show me a purely algebraic approach. I can't connect those elements (two equations). I solve fast via the common sense, but I it looks like I am doing something silly on the proportions side.

I have this ready, after taking out three 0's, \(26t = 3800\) (after 3800/t=26), and then since we have \(11t=s\) it must be that \(\frac{s}{11}=\frac{t}{1}\)? But then, if it is true, I am confused with my common sense...please help me untangle myself. How do you express ratios as stated in the problem?



chica,

This calculation is v easy if you know 13^2 = 169.

3380000/ 26000 = 3380/26 = 1690/13 = 130
User avatar
Intern
Intern
Joined: 06 Feb 2013
Posts: 35
Own Kudos [?]: 206 [0]
Given Kudos: 35
Send PM
Re: PS: Please, advise on how to calculate quicker!!! [#permalink]
Quote:
chica,

This calculation is v easy if you know 13^2 = 169.

3380000/ 26000 = 3380/26 = 1690/13 = 130


Dude, I appreciate your effort, but I am not looking for a solution, I am looking for a specific way to solve, the one I need to get a grasp of.

Thanks.
avatar
Intern
Intern
Joined: 30 Aug 2013
Posts: 2
Own Kudos [?]: 1 [1]
Given Kudos: 0
Send PM
Re: PS: Please, advise on how to calculate quicker!!! [#permalink]
obs23 wrote:
Could someone show me a purely algebraic approach. I can't connect those elements (two equations). I solve fast via the common sense, but I it looks like I am doing something silly on the proportions side.

I have this ready, after taking out three 0's, \(26t = 3800\) (after 3800/t=26), and then since we have \(11t=s\) it must be that \(\frac{s}{11}=\frac{t}{1}\)? But then, if it is true, I am confused with my common sense...please help me untangle myself. How do you express ratios as stated in the problem?




This is an arithmetic question, using algebra and adding variables only makes this problem complicated. Additionally, you shouldn't be concerned about expressing the solution in ratios if that doesn't appear as an answer form. But regarding your equation. Your math is correct s/11 = t/1 (This is confirmed through backsolving with the arithmetic... 1430/11 = 130/1) But this proportion doesn't actually give you the answer to the problem since there are two unsolved variables, so I'm not sure what use it is.
User avatar
Intern
Intern
Joined: 06 Feb 2013
Posts: 35
Own Kudos [?]: 206 [0]
Given Kudos: 35
Send PM
Re: PS: Please, advise on how to calculate quicker!!! [#permalink]
VeritasPrepRon wrote:
obs23 wrote:
Could someone show me a purely algebraic approach. I can't connect those elements (two equations). I solve fast via the common sense, but I it looks like I am doing something silly on the proportions side.

I have this ready, after taking out three 0's, \(26t = 3800\) (after 3800/t=26), and then since we have \(11t=s\) it must be that \(\frac{s}{11}=\frac{t}{1}\)? But then, if it is true, I am confused with my common sense...please help me untangle myself. How do you express ratios as stated in the problem?


Hi obs, if you're intent on solving the question through ratios, then you can, but it's not necessarily the best approach. That being said, let's attack it as a ratio problem.

Firstly, there's a slight typo in how you copied the math, it's actually \(26t = 3,380\). You can then figure out that whatever t is, if you multiply it by 11 you'll get the number of students. So yes \(\frac{s}{11}=\frac{t}{1}\), and you already have \(26t = 3,380\) so \(t= \frac{3,380}{26}\). Now solve t for 130, and then \(11t=s\). s is 1430.


A sneakier way to solve this:

The GMAT will always try and trap you, so if it asks for the number of students (s), the number of teachers (t) will also be a trap answer somewhere on the list. If you recognize this, then all you have to do is look for the two answer choices that are 11 away from one another. The bigger one will be the answer and the smaller will be the trap. This kind of "fourth wall" shortcut isn't for everyone, but it can be very helpful when crunched for time or unsure about the math.

Hope this helps!
-Ron


Thanks Ron, all makes sense. As for the use, I was just a bit rusty on ratios so I wanted to make sure I do the simple stuff correctly in algebraic terms.
User avatar
Veritas Prep GMAT Instructor
Joined: 11 Dec 2012
Posts: 310
Own Kudos [?]: 633 [0]
Given Kudos: 66
Send PM
Re: A certain college has a student-to-teacher ratio of 11 to 1. [#permalink]
Expert Reply
No problem obs23, as mentioned it may not be the most obvious way to solve this problem, but I like to remind students that pretty much any GMAT math problem can be solved in a variety of ways. If you have one way to solve the problem, you're probably okay, but if you have three different ways, then you're definitely in great shape to solve any variation of the problem on test day. Hope this makes sense!

-Ron
Intern
Intern
Joined: 26 Apr 2017
Posts: 7
Own Kudos [?]: 5 [0]
Given Kudos: 1
Send PM
Re: A certain college has a student-to-teacher ratio of 11 to 1. [#permalink]
Easy

13^2 = 169.

3380000/ 26000 = 3380/26 = 1690/13 = 130

:)
Intern
Intern
Joined: 07 Feb 2021
Posts: 18
Own Kudos [?]: 4 [0]
Given Kudos: 7
Send PM
Re: A certain college has a student-to-teacher ratio of 11 to 1. [#permalink]
Can we say that the answer will be multiple of 11 and 1430 is the only one ?
Intern
Intern
Joined: 15 Feb 2021
Posts: 17
Own Kudos [?]: 4 [0]
Given Kudos: 24
Send PM
Re: A certain college has a student-to-teacher ratio of 11 to 1. [#permalink]
Quite easy. Divide total salaries paid by average annual salary. Remove the zeros if you want to make the division easier.

3380/26 = 130 teachers in the college.

No. of students = 11 times no. of teachers = 11 x 130

Easy way to multiply a number by 11: write the number in a row. Write the same number in a row below with the units digit of number in second row under the 10s digit of the number in first row. Add.

130
130
_____
1,430

Total no. of students = 1,430

Regards

Arun Krishnan
GMAT with AK


chica wrote:
A certain college has a student-to-teacher ratio of 11 to 1. The average (arithmetic mean) annual salary for teachers is $26,000. If the college pays a total of $3,380,000 in annual salaries to its teachers, how many students does the college have ?

(A) 130
(B) 169
(C) 1,300
(D) 1,430
(E) 1,560

Hi, this is a pretty easy question, I know. Still, It took me a bit more than 3 min to perform all the calculation.. :oops: Are there any tips on how to calculate everything quicker? In general, I will greatly appreciate if anyone can share any ideas on how to do calculations quickly.. Calculations of fractions-decimals or just large numbers take my time. moreover I just tend to make careless mistakes here being pressed on time.......Please, advise..

Thanks much
GMAT Club Bot
Re: A certain college has a student-to-teacher ratio of 11 to 1. [#permalink]
Moderators:
Math Expert
92915 posts
Senior Moderator - Masters Forum
3137 posts

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