It is currently 17 Dec 2017, 19:29

### 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

# How many times will the digit 7 be written when listing the

Author Message
VP
Joined: 09 Jul 2007
Posts: 1098

Kudos [?]: 149 [0], given: 0

Location: London
How many times will the digit 7 be written when listing the [#permalink]

### Show Tags

12 Nov 2007, 06:42
This topic is locked. If you want to discuss this question please re-post it in the respective forum.

How many times will the digit 7 be written when listing the integers from 1 to 1000?

110
111
271
300
304

Kudos [?]: 149 [0], given: 0

Manager
Joined: 01 Nov 2007
Posts: 68

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

### Show Tags

12 Nov 2007, 08:08
D

300 times

100 times at units place
100 times at tens place
100 times at hundreds place

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

VP
Joined: 09 Jul 2007
Posts: 1098

Kudos [?]: 149 [0], given: 0

Location: London

### Show Tags

12 Nov 2007, 09:04

Kudos [?]: 149 [0], given: 0

Senior Manager
Joined: 01 Sep 2006
Posts: 301

Kudos [?]: 29 [0], given: 0

Location: Phoenix, AZ, USA

### Show Tags

12 Nov 2007, 09:51
Ravshonbek wrote:
How many times will the digit 7 be written when listing the integers from 1 to 1000?

110
111
271
300
304

b/1 1-100 10 times + 1 for (77) =11
b/w 101-200 10 times + 1 more time (177) =11
b/w 201-300 10 times + 1 more time (277) = 11
b/w301-400 10 times + 1 more time (377) =11
b/w401-400 10 times + 1 more time (477) = 11
b/w501-600 10 times + 1 more time (577)= 11
b/w601-700 10 times + 1 more time (677)=11
b/w701-800 10 times + 10 times (for 7 being 1st digit) + 1 (777)=21
b/w 801-900 10 times + 1 more time (877) =11
b/w 901-1000 10 times + 1 more time (977) =11

99+11+1= 111

Kudos [?]: 29 [0], given: 0

Director
Joined: 25 Oct 2006
Posts: 633

Kudos [?]: 656 [0], given: 6

### Show Tags

12 Nov 2007, 10:12
a) Unit’s place : i.e. 7,17,27,37…..97 = 10 times (between 1 to 100)
b) Tenth’s place: i.e. 70,71…79 = 10 times (between 1 to 100)
c) Hundred’s place: i.e. 700,701…..799= 100 times

So Upto 1000 it would be ten times for a and b: 10*10+10*10+100 = 300

D

Kudos [?]: 656 [0], given: 6

CEO
Joined: 21 Jan 2007
Posts: 2734

Kudos [?]: 1091 [0], given: 4

Location: New York City

### Show Tags

07 Jan 2008, 11:40
Ravshonbek wrote:

1000 is a 4 digit integer. XXXX
control for each of the digits.

the first digit cannot be 7 so we only have xxx to control for.

controlling for hundreds digit
7xx - the tens place can be 10C1 and the ones place can be 10C1. therefore, 10*10 = 100 possibilities
x7x - same logic
xx7 - same logic

100 + 100 + 100 = 300
_________________

You tried your best and you failed miserably. The lesson is 'never try'. -Homer Simpson

Kudos [?]: 1091 [0], given: 4

Intern
Joined: 07 Jan 2008
Posts: 21

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

### Show Tags

07 Jan 2008, 13:35
300..

between
1 and 100 – 20 times
101 and 200 – 20
201 and 300 – 20
301 and 400 – 20
401 and 500 – 20
501 and 600 – 20
601 and 700 – 20 + 1
701 and 800 – 20 + 99
801 and 900 – 20
901 and 1000 – 20

i.e 300

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

Re: 7   [#permalink] 07 Jan 2008, 13:35
Display posts from previous: Sort by

# How many times will the digit 7 be written when listing the

Moderator: chetan2u

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