5). How many times is the digit "3" written while : PS Archive
Check GMAT Club Decision Tracker for the Latest School Decision Releases http://gmatclub.com/AppTrack

 It is currently 23 Jan 2017, 21:07

### 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

# 5). How many times is the digit "3" written while

Author Message
Manager
Joined: 04 Sep 2007
Posts: 215
Followers: 1

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

5). How many times is the digit "3" written while [#permalink]

### Show Tags

16 May 2008, 07:06
00:00

Difficulty:

(N/A)

Question Stats:

100% (00:00) correct 0% (00:00) wrong based on 0 sessions

### HideShow timer Statistics

This topic is locked. If you want to discuss this question please re-post it in the respective forum.

5). How many times is the digit "3" written while numbering the pages of a book from 1 to 1000?
A. 243
B. 252
C. 271
D. 293
E. 300

Any easy/quick way to solve this?
Director
Joined: 23 Sep 2007
Posts: 789
Followers: 5

Kudos [?]: 185 [0], given: 0

Re: PS: Counting the Digits [#permalink]

### Show Tags

16 May 2008, 09:19
not sure if this is a quick way

<edit>from 30 to 39, there are 11 3s <edit>
from 0 to 100 there are 20 3's (with the 30s)

not counting 300s, 20*9 = 180 3s between 0 and 1000

from 300 to 399, there are a 100 3s from the hundreds digit
and 20 3s from the tens digit

what is the oa?

Last edited by gmatnub on 16 May 2008, 09:42, edited 1 time in total.
Manager
Joined: 04 Sep 2007
Posts: 215
Followers: 1

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

Re: PS: Counting the Digits [#permalink]

### Show Tags

16 May 2008, 09:36
OA is 300. You are darn right, GMATnub. Good job, mate.
Current Student
Joined: 28 Dec 2004
Posts: 3384
Location: New York City
Schools: Wharton'11 HBS'12
Followers: 15

Kudos [?]: 283 [0], given: 2

Re: PS: Counting the Digits [#permalink]

### Show Tags

16 May 2008, 09:44
number of ways to have 3s..hmm

well we can have 3 as the unit digit..in that case we can have 10 different hundreds and 10 different ways of tens...10*10*1+10*1*10 (this case when 3 is the ten digit)+1*10*10 (this case when 3 is hundred digit)..total 100+100+100=300
CEO
Joined: 17 Nov 2007
Posts: 3589
Concentration: Entrepreneurship, Other
Schools: Chicago (Booth) - Class of 2011
GMAT 1: 750 Q50 V40
Followers: 550

Kudos [?]: 3565 [0], given: 360

Re: PS: Counting the Digits [#permalink]

### Show Tags

16 May 2008, 10:37
in the set of the numbers {001,002,003,...,999} we have 1000 numbers with 3 digits, totally 3000. Appearance of 3 is 1/10. So, N=3000*1/10=300
_________________

HOT! GMAT TOOLKIT 2 (iOS) / GMAT TOOLKIT (Android) - The OFFICIAL GMAT CLUB PREP APP, a must-have app especially if you aim at 700+ | PrepGame

Director
Joined: 14 Oct 2007
Posts: 758
Location: Oxford
Schools: Oxford'10
Followers: 15

Kudos [?]: 214 [0], given: 8

Re: PS: Counting the Digits [#permalink]

### Show Tags

17 May 2008, 04:40
we have:

1000 numbers with probability of a 3 appearing in each respective place equal to 0, 1/10, 1/10 ,1/10

so our overall probablity = 3/10. multiplying this with our 1000 numbers gives us 300.
Re: PS: Counting the Digits   [#permalink] 17 May 2008, 04:40
Display posts from previous: Sort by