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

 It is currently 21 Mar 2019, 08:55

### 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

# Last year members of a certain professional organization for teachers

Author Message
TAGS:

### Hide Tags

Math Expert
Joined: 02 Sep 2009
Posts: 53768
Last year members of a certain professional organization for teachers  [#permalink]

### Show Tags

01 Aug 2018, 11:30
1
25
00:00

Difficulty:

45% (medium)

Question Stats:

70% (01:56) correct 30% (02:05) wrong based on 555 sessions

### HideShow timer Statistics

Last year members of a certain professional organization for teachers consisted of teachers from 49 different school districts, with an average (arithmetic mean) of 9.8 schools per district. Last year the average number of teachers at these schools who were members of the organization was 22. Which of the following is closest to the total number of members of the organization last year?

A. 10^7
B. 10^6
C. 10^5
D. 10^4
E. 10^3

NEW question from GMAT® Quantitative Review 2019

(PS12450)

_________________
Intern
Joined: 04 May 2014
Posts: 45
Concentration: Strategy, Operations
Re: Last year members of a certain professional organization for teachers  [#permalink]

### Show Tags

02 Aug 2018, 00:28
Bunuel wrote:
Last year members of a certain professional organization for teachers consisted of teachers from 49 different school districts, with an average (arithmetic mean) of 9.8 schools per district. Last year the average number of teachers at these schools who were members of the organization was 22. Which of the following is closest to the total number of members of the organization last year?

A. 107
B. 106
C. 105
D. 104
E. 103

NEW question from GMAT® Quantitative Review 2019

(PS12450)

Pls provide solution to this problem. I thought it to be simple average question and multiplied all the figures as
1) Total schools = Average schools per districts x Number of districts = 9.8 x 49
2) Total number of members of the organization = Average number of teachers at each schools x Total Schools = (9.8 x 49) x 22

It gave huge number.. .
Intern
Joined: 16 Jul 2018
Posts: 1
Re: Last year members of a certain professional organization for teachers  [#permalink]

### Show Tags

02 Aug 2018, 23:22
1
The number of schools do not result a whole number from the given info. Pls check the question

Posted from my mobile device
Math Expert
Joined: 02 Sep 2009
Posts: 53768
Re: Last year members of a certain professional organization for teachers  [#permalink]

### Show Tags

02 Aug 2018, 23:28
The number of schools do not result a whole number from the given info. Pls check the question

Posted from my mobile device

Exponent signs were missing. Edited. Thank you.
_________________
Manager
Joined: 31 Jul 2017
Posts: 138
Location: Tajikistan
Concentration: Finance, Economics
Schools: Booth '21, CBS '21
GMAT 1: 690 Q48 V35
GRE 1: Q164 V162
GPA: 3.85
WE: Accounting (Investment Banking)
Re: Last year members of a certain professional organization for teachers  [#permalink]

### Show Tags

02 Aug 2018, 23:35
1
1
We have 49 districts with average of 9.8 schools in one district, with 22 teachers from each school. So, we have 49*9.8*22=5*10*10*10*2=10^3(5*2)=10^4 (D)
Director
Status: Learning stage
Joined: 01 Oct 2017
Posts: 966
WE: Supply Chain Management (Energy and Utilities)
Re: Last year members of a certain professional organization for teachers  [#permalink]

### Show Tags

03 Aug 2018, 06:52
2
Bunuel wrote:
Last year members of a certain professional organization for teachers consisted of teachers from 49 different school districts, with an average (arithmetic mean) of 9.8 schools per district. Last year the average number of teachers at these schools who were members of the organization was 22. Which of the following is closest to the total number of members of the organization last year?

A. 10^7
B. 10^6
C. 10^5
D. 10^4
E. 10^3

NEW question from GMAT® Quantitative Review 2019

(PS12450)

Total no of schools=Avg. no of schools per district*Total no of districts=9.8*49
Total no of members=Avg. no. of teachers per school*Total no of schools=$$49*(9.8*22)= (\approx{50})*(\approx{10})*(\approx{20})=10^4$$

Ans. (D)
_________________

Regards,

PKN

Rise above the storm, you will find the sunshine

Intern
Joined: 19 Dec 2017
Posts: 2
Re: Last year members of a certain professional organization for teachers  [#permalink]

### Show Tags

07 Aug 2018, 19:50
tatz wrote:
Bunuel wrote:
Last year members of a certain professional organization for teachers consisted of teachers from 49 different school districts, with an average (arithmetic mean) of 9.8 schools per district. Last year the average number of teachers at these schools who were members of the organization was 22. Which of the following is closest to the total number of members of the organization last year?

A. 107
B. 106
C. 105
D. 104
E. 103

NEW question from GMAT® Quantitative Review 2019

(PS12450)

Pls provide solution to this problem. I thought it to be simple average question and multiplied all the figures as
1) Total schools = Average schools per districts x Number of districts = 9.8 x 49
2) Total number of members of the organization = Average number of teachers at each schools x Total Schools = (9.8 x 49) x 22

It gave huge number.. .

I solved this question by rounding it off to the nearest integer values i.e. 10*50*22. i.e. 11000 and the nearest value of 11000 is 10000 i.e. 10^4.
Target Test Prep Representative
Status: Founder & CEO
Affiliations: Target Test Prep
Joined: 14 Oct 2015
Posts: 5381
Location: United States (CA)
Re: Last year members of a certain professional organization for teachers  [#permalink]

### Show Tags

10 Aug 2018, 18:35
1
Bunuel wrote:
Last year members of a certain professional organization for teachers consisted of teachers from 49 different school districts, with an average (arithmetic mean) of 9.8 schools per district. Last year the average number of teachers at these schools who were members of the organization was 22. Which of the following is closest to the total number of members of the organization last year?

A. 10^7
B. 10^6
C. 10^5
D. 10^4
E. 10^3

Since there are 49 districts and an average of 9.8 schools per district, there are 49 x 9.8 schools in total. Furthermore, since there are on average 22 teachers per school, the total number of teachers is 49 x 9.8 x 22, which is approximately 50 x 10 x 22 = 11,000. We see that this is closest to 10^4.

_________________

# Scott Woodbury-Stewart

Founder and CEO

Scott@TargetTestPrep.com
122 Reviews

5-star rated online GMAT quant
self study course

See why Target Test Prep is the top rated GMAT quant course on GMAT Club. Read Our Reviews

Manager
Joined: 10 Apr 2018
Posts: 199
Re: Last year members of a certain professional organization for teachers  [#permalink]

### Show Tags

15 Aug 2018, 22:31
Hi,
Total number of schools in 49 Districts/ number of districts= Avg Schools Per district.
So
Total number of schools in 49 Districts / 49= 9.8,
=>total number of schools in 49 districts is 49*9.8 or 50 *10=500 { rounding 9.8 to 10 and rounding 49 to 50}

Now total number teachers in the 49 school/ total number of schools = Avg teacher per school

Total number of teachers in 49 schools= 500*22 or 500*20=10000 which is 10^4

Probus
_________________

Probus

e-GMAT Representative
Joined: 04 Jan 2015
Posts: 2717
Re: Last year members of a certain professional organization for teachers  [#permalink]

### Show Tags

17 Aug 2018, 01:43

Solution

Given:
• Last year, certain professional organization consisted of teachers from 49 different school districts
• Average number of schools per district = 9.8
• Average number of teachers, at these schools, who were members of the organization = 22

To find:
• Which of the given answer choices is closest to the total number of members of the organization last year

Approach and Working:
• Average number of schools per district = total number of schools/ total number of districts.
o Implies, total number of schools = total number of districts * average number of schools per district
o Thus, total number of schools = 49 x 9.8
• And, average number of teachers at these schools, who were members = total number of teachers, who were members/total number of schools
o Implies, total number of members of organization = average number of teachers at these schools, who were members * total number of schools
o Thus, the total number of members of organization = (49 x 9.8) x 22 ≃ 50 x 10 x 20 = $$10^4$$

Therefore, the total number of members of the organization last year = 104

Hence, the correct answer is option D.

_________________

| '4 out of Top 5' Instructors on gmatclub | 70 point improvement guarantee | www.e-gmat.com

Manager
Joined: 07 Feb 2017
Posts: 184
Re: Last year members of a certain professional organization for teachers  [#permalink]

### Show Tags

17 Aug 2018, 10:13
9.8 schools/district * 49 district * 22 teachers/school
Round to 10*50*20=10,000=10^4
Manager
Joined: 06 Sep 2018
Posts: 175
Location: Pakistan
Concentration: Finance, Operations
GPA: 2.87
WE: Engineering (Other)
Re: Last year members of a certain professional organization for teachers  [#permalink]

### Show Tags

24 Sep 2018, 21:48
total number of members=49*10(approx of 9.8)*22=490*22=490*20(approx)=9800=10^4 (approx)
_________________

Hitting Kudos is the best way of appreciation.

Eric Thomas, "When you want to succeed as bad as you want to breathe, then you'll be successful."

Intern
Joined: 03 Sep 2018
Posts: 22
WE: Analyst (Consulting)
Re: Last year members of a certain professional organization for teachers  [#permalink]

### Show Tags

03 Nov 2018, 07:12
tatz wrote:
Bunuel wrote:
Last year members of a certain professional organization for teachers consisted of teachers from 49 different school districts, with an average (arithmetic mean) of 9.8 schools per district. Last year the average number of teachers at these schools who were members of the organization was 22. Which of the following is closest to the total number of members of the organization last year?

A. 107
B. 106
C. 105
D. 104
E. 103

NEW question from GMAT® Quantitative Review 2019

(PS12450)

Pls provide solution to this problem. I thought it to be simple average question and multiplied all the figures as
1) Total schools = Average schools per districts x Number of districts = 9.8 x 49
2) Total number of members of the organization = Average number of teachers at each schools x Total Schools = (9.8 x 49) x 22

It gave huge number.. .

Answer: We can solve it by rounding off the numbers

Total members(teachers) = Total school districts * Total school per district * avg teacher per school
= 49 * 9.8 * 22

Now since the options in the original question question are given in terms of power of ten, so
Total teachers = 50 * 10 * 2*10 = 5*2*10^3 = 10^4
_________________

Regards,
Bashdeep

Let's study and grow together
If the answer helped you, be generous and hit +1 Kudos

Manager
Status: GMAT - Pulling Quant and Verbal together
Joined: 04 Sep 2017
Posts: 133
GPA: 3.6
WE: Sales (Computer Software)
Re: Last year members of a certain professional organization for teachers  [#permalink]

### Show Tags

20 Feb 2019, 06:43
Bunuel wrote:
Last year members of a certain professional organization for teachers consisted of teachers from 49 different school districts, with an average (arithmetic mean) of 9.8 schools per district. Last year the average number of teachers at these schools who were members of the organization was 22. Which of the following is closest to the total number of members of the organization last year?

A. 10^7
B. 10^6
C. 10^5
D. 10^4
E. 10^3

I rounded these numbers and then factored them. Came up with a very quick solution.

49 Districts | 9.8 Schools | 22 Teachers

Step 1) Round

50 Districts | 10 Schools | 20 Teachers

Step 2) Factor to easy numbers

5 * 10 | 10 | 10 * 2

Step 3) Multiply

$$10^3$$ * 5*2 = $$10^4$$
_________________

Would I rather be feared or loved? Easy. Both. I want people to be afraid of how much they love me.

How to sort questions by Topic, Difficulty, and Source:
https://gmatclub.com/forum/search.php?view=search_tags

Re: Last year members of a certain professional organization for teachers   [#permalink] 20 Feb 2019, 06:43
Display posts from previous: Sort by