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

It is currently 18 Apr 2014, 03:27

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.

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

M07#37

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
2 KUDOS received
Intern
Intern
Joined: 15 Nov 2008
Posts: 7
Followers: 0

Kudos [?]: 2 [2] , given: 0

GMAT Tests User
M07#37 [#permalink] New post 26 Dec 2008, 11:51
2
This post received
KUDOS
00:00
A
B
C
D
E

Difficulty:

  55% (medium)

Question Stats:

58% (02:33) correct 41% (02:00) wrong based on 162 sessions
A construction company wants to number new houses using digit plates only. If the company puts an order for 1212 plates how many houses are to be given numbers? (The numbers of houses are consecutive and the number of the first house is 1).

(A) 260
(B) 440
(C) 556
(D) 792
(E) 1200

[Reveal] Spoiler: OA
B

Source: GMAT Club Tests - hardest GMAT questions

Could someone provide alternative solution, the provided solution is not clear ...?
thanks.
[Reveal] Spoiler: OA
Kaplan Promo CodeKnewton GMAT Discount CodesGMAT Pill GMAT Discount Codes
3 KUDOS received
CEO
CEO
User avatar
Joined: 29 Aug 2007
Posts: 2504
Followers: 48

Kudos [?]: 452 [3] , given: 19

GMAT Tests User
Re: M07#37 [#permalink] New post 26 Dec 2008, 16:36
3
This post received
KUDOS
gmatclub1 wrote:
A construction company wants to number new houses using digit plates only. If the company puts an order for 1212 plates how many houses are to be given numbers? (The numbers of houses are consecutive and the number of the first house is 1).
1) 260
2) 440
3) 556
4) 792
5) 1200

Could someone provide alternative solution, the provided solution is not clear ...?
thanks.


Plates req for 1 digit plates = 1-9 = 9
Plates req for 2 digit plates = 10-99 = 90
Plates req for 3 digit plates = 100- up = needs to find.

1,212 = plates req for single digit + plates req for two digits + plates req for three digit
1,212 = 9 (n) + 90 (2n) + x (3n)
x = (1,212 - 9 - 180)/3 (since n = 1)
x = 341

no of houses = 9 + 90 + 341 = 440.
_________________

Verbal: new-to-the-verbal-forum-please-read-this-first-77546.html
Math: new-to-the-math-forum-please-read-this-first-77764.html
Gmat: everything-you-need-to-prepare-for-the-gmat-revised-77983.html


GT

Intern
Intern
Joined: 29 Jul 2009
Posts: 17
Followers: 0

Kudos [?]: 5 [0], given: 6

Re: M07#37 [#permalink] New post 14 Aug 2009, 23:21
Gmat tiger,

I'm trying to understand your alternative solution, but I believe the calculation is incorrect:

1,212 = plates req for single digit + plates req for two digits + plates req for three digit
1,212 = 9 (n) + 90 (2n) + x (3n)
x = (1,212 - 9 - 90)/3 (since n = 1)
x = 341 <----- this should be 371 according the the statement preceding it
1 KUDOS received
CEO
CEO
User avatar
Joined: 29 Aug 2007
Posts: 2504
Followers: 48

Kudos [?]: 452 [1] , given: 19

GMAT Tests User
Re: M07#37 [#permalink] New post 15 Aug 2009, 17:22
1
This post received
KUDOS
dpgxxx wrote:
Gmat tiger,

I'm trying to understand your alternative solution, but I believe the calculation is incorrect:

1,212 = plates req for single digit + plates req for two digits + plates req for three digit
1,212 = 9 (n) + 90 (2n) + x (3n)
x = (1,212 - 9 - 90)/3 (since n = 1)
x = 341 <----- this should be 371 according the the statement preceding it


341 is correct but the highlighted 90 should be 180.

Thanks. 8-)
_________________

Verbal: new-to-the-verbal-forum-please-read-this-first-77546.html
Math: new-to-the-math-forum-please-read-this-first-77764.html
Gmat: everything-you-need-to-prepare-for-the-gmat-revised-77983.html


GT

Manager
Manager
Joined: 14 Apr 2010
Posts: 233
Followers: 2

Kudos [?]: 11 [0], given: 1

GMAT Tests User
Re: M07#37 [#permalink] New post 20 Jul 2010, 00:47
Is this qs too difficult? I can't get any of the solutions provided....somebody please step in and help:-(
6 KUDOS received
Manager
Manager
Joined: 02 Apr 2010
Posts: 103
Followers: 3

Kudos [?]: 87 [6] , given: 18

Re: M07#37 [#permalink] New post 20 Jul 2010, 03:45
6
This post received
KUDOS
The solution is as outlined by Gmat tiger.

You can number the first 9 houses with a single digits plate each (i.e. 1st house with 1, 2nd house with 2...9nth house with 9). => You have numbered 9 houses and you have 1212 - 9 = 1203 digits plates left.

Then you start numbering houses 10 to 99 with two digits plates each (i.e. 11th house with 11....99th house with 99). => You have numbered 99 houses and you have 1212 - 9 - 2*90 = 1023 digits plates left.

Now you know that from now on you need 3 digits plates to number each house. Since you have 1023 digits plates left you can number 1023 / 3 = 341 additional houses

So in total you can number 9 + 90 + 341 = 440 houses.
Manager
Manager
Joined: 20 Jul 2010
Posts: 198
Followers: 2

Kudos [?]: 53 [0], given: 7

GMAT Tests User
Re: M07#37 [#permalink] New post 13 Aug 2010, 08:50
IMO B..
very good question
_________________

Gotta hit the 700 score this time... 3rd time lucky !
Give me some kudos... Like you, even I need them badly ;)

Intern
Intern
Joined: 01 Jun 2010
Posts: 7
Followers: 0

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

Re: M07#37 [#permalink] New post 13 Aug 2010, 10:42
How did the Question lead us to think that we need to determine # of houses with 3 digits?
Why not 4?

I am not able to determine what is asked here.
Intern
Intern
Joined: 10 Jan 2010
Posts: 25
Followers: 0

Kudos [?]: 1 [0], given: 32

Re: M07#37 [#permalink] New post 13 Aug 2010, 17:33
GMAT TIGER wrote:
dpgxxx wrote:
Gmat tiger,

I'm trying to understand your alternative solution, but I believe the calculation is incorrect:

1,212 = plates req for single digit + plates req for two digits + plates req for three digit
1,212 = 9 (n) + 90 (2n) + x (3n)
x = (1,212 - 9 - 90)/3 (since n = 1)
x = 341 <----- this should be 371 according the the statement preceding it


341 is correct but the highlighted 90 should be 180.

Thanks. 8-)


We need the total number of houses not plates per house---90 is correct.
Director
Director
Joined: 21 Dec 2009
Posts: 588
Concentration: Entrepreneurship, Finance
Followers: 15

Kudos [?]: 201 [0], given: 20

GMAT Tests User
Re: M07#37 [#permalink] New post 13 Aug 2010, 23:15
Quote:
The numbers of houses are consecutive and the number of the first house is 1

How does the underlined text (or any other one) suggest that there is only a digit per plate? I thought consecutive numbers of houses means 1,2,3, ..., 10, 11, ..100, 101,...
Also, there could be double digit plates, three-digit plates, etc...

Someone please correct my erroneous statement.
_________________

KUDOS me if you feel my contribution has helped you.

Intern
Intern
Joined: 10 Jan 2010
Posts: 25
Followers: 0

Kudos [?]: 1 [0], given: 32

Re: M07#37 [#permalink] New post 14 Aug 2010, 05:27
The construction company is using "digit plates," i.e., no S is added to digit, thus a single digit per plate.

Last edited by GaryDunn on 14 Aug 2010, 14:48, edited 2 times in total.
Manager
Manager
Joined: 12 Jul 2010
Posts: 68
Followers: 1

Kudos [?]: 2 [0], given: 3

Re: M07#37 [#permalink] New post 17 Aug 2010, 00:32
Its B.

9 nos with 1 digit (1-9) & 90 nos with 2 digit (10-99) and the rest are 3 digit nos!

1*9 + 2*90 + 3*(x) = 1212

So x=341

9+90+341= 440
Manager
Manager
Joined: 27 May 2010
Posts: 203
Followers: 2

Kudos [?]: 9 [0], given: 3

GMAT Tests User
Re: M07#37 [#permalink] New post 22 Aug 2010, 04:58
9+ 2*90 + 3*x = 1212 => 341 ==> 440 houses to be given numbers.

GMAT tiger gave a good explanation, but i usually just try to solve it practically.
Intern
Intern
Joined: 18 Jun 2010
Posts: 26
Followers: 0

Kudos [?]: 4 [0], given: 6

Re: M07#37 [#permalink] New post 30 Aug 2010, 22:44
why isnt the 4 digits being used?
Manager
Manager
Joined: 23 Jan 2011
Posts: 129
Followers: 1

Kudos [?]: 7 [0], given: 12

Re: M07#37 [#permalink] New post 06 Jul 2011, 12:46
I think the question may be a bit ambiguous to some. Would be helpful to mention smthing such as 1 digit equals 1 plate? What say?
Manager
Manager
Joined: 11 Aug 2011
Posts: 77
Location: United States
Concentration: Economics, Finance
GMAT Date: 10-16-2013
GPA: 3
WE: Analyst (Computer Software)
Followers: 0

Kudos [?]: 19 [0], given: 138

Re: M07#37 [#permalink] New post 17 Aug 2011, 09:15
I used the elimination technique to find out the correct answer here.
Now lets see how this works :

Number of plates for numbers from 1-9 ->9
Number of plates for number 10-99 ->90x2 = 180
Number of plates for numbers 100-199 ->100x3 =300
similarly for 200-299 -> 300
300-399 -> 300
400-499 -> 300

from the options which are given if we add number of plates required only for number from 100-499 it should be 1200 the number of plates required are a little more than this hence our answer should be very close to 400 and hence the answer
1 KUDOS received
Manager
Manager
User avatar
Status: Dreaming High
Joined: 24 Apr 2011
Posts: 61
Location: India
Concentration: Operations, Strategy
GMAT 1: 720 Q50 V36
GPA: 3.28
WE: Project Management (Manufacturing)
Followers: 0

Kudos [?]: 11 [1] , given: 14

Re: M07#37 [#permalink] New post 17 Aug 2011, 22:10
1
This post received
KUDOS
ya really a tricky question,

the trick is in the sentence "construction company wants to number new houses using digit plates only"..
so it means in each board only one digit will be written.

so for the first 9 houses, which wil be numbered as, 1,2,3..9, we need 9 plates
for the 10th house, the house number should be 10 ( because "numbers of houses are consecutive")
so for the 10th house, two plates are required ( a plate with the number 1 and a plate with the number 0)
hence for the next 90 houses ( obtained as 99-10), we need 90 * 2 plates = 180 plates

and nw the equation comes 1*9 + 2*90 + 3*a = 1212 ==> a = 341
and number of houses = 9 +90+341 = 440

*** 4 digits are not considered because it is mentioned that "numbers of houses are consecutive"
_________________

[caption=]Remember: Anything that can go wrong, will go wrong.[/caption]

Intern
Intern
Joined: 07 Jun 2011
Posts: 25
Followers: 0

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

Re: M07#37 [#permalink] New post 18 Aug 2011, 03:02
You don't have to go to 4 digits because 3*900 is greater than the number of plates (1212)

I made the same mistake; I did not take in to account the number of plates, i.e, when we use 2 digit plates, you have to multiply the various arrangements by the number of plates
Senior Manager
Senior Manager
Joined: 19 Oct 2010
Posts: 272
Location: India
GMAT 1: 560 Q36 V31
GPA: 3
Followers: 6

Kudos [?]: 25 [0], given: 26

GMAT Tests User
Re: M07#37 [#permalink] New post 03 Sep 2011, 22:37
The answer is B.

I used the answers to solve this problem. This was my approach:
Firstly, irrespective of which choice the answer is:
Houses 1 thru 9 require 9 plates
Houses 10 thru 99 require 180 plates (90 * 2)
Houses 100 and above require 3x plates

If we were to now use the answer choices:
(1) Too small a number.
(2) 440 => 9 + 180 + (440 - 99)3
= 189 + (341)3
= 189 + 1023
= 1212
(3), (4) and (5) yield a number higher than 1212
_________________

petrifiedbutstanding

Intern
Intern
Status: gmat fresher
Joined: 07 Jun 2012
Posts: 25
GPA: 3.87
Followers: 5

Kudos [?]: 134 [0], given: 12

Re: M07#37 [#permalink] New post 21 Aug 2012, 04:52
single numbers =9 plates
doublenumbers =90 *2=180 plates
triple numbers=---*3=1023 plates-->as total number of plates=1212
so triple numbers=341
hence total houses numbered =9+90+341=440

:-D
Re: M07#37   [#permalink] 21 Aug 2012, 04:52
Display posts from previous: Sort by

M07#37

  Question banks Downloads My Bookmarks Reviews Important topics  

Go to page    1   2    Next  [ 26 posts ] 

Moderators: Bunuel, WoundedTiger



GMAT Club MBA Forum Home| About| Privacy Policy| Terms and Conditions| GMAT Club Rules| Contact| Sitemap

Powered by phpBB © phpBB Group and phpBB SEO

Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.