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

 It is currently 01 Jul 2016, 01:37

### 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

# One writes a list of numbers from 1 to 1000. How many ones

 post reply Question banks Downloads My Bookmarks Reviews Important topics
Author Message
SVP
Joined: 03 Feb 2003
Posts: 1603
Followers: 8

Kudos [?]: 181 [0], given: 0

One writes a list of numbers from 1 to 1000. How many ones [#permalink]

### Show Tags

26 Sep 2003, 12:05
00:00

Difficulty:

(N/A)

Question Stats:

0% (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.

One writes a list of numbers from 1 to 1000. How many ones will he have to write?
SVP
Joined: 03 Feb 2003
Posts: 1603
Followers: 8

Kudos [?]: 181 [0], given: 0

### Show Tags

27 Sep 2003, 08:28
guys, what are you waiting for? give it a try.
Manager
Joined: 13 Aug 2003
Posts: 68
Location: India
Followers: 1

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

### Show Tags

29 Sep 2003, 06:50
a tricky one... just giving a shot though... hundrets place 100 + tens place 90 and units 90 == 280.. not too sure still...
Manager
Joined: 13 Aug 2003
Posts: 68
Location: India
Followers: 1

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

### Show Tags

29 Sep 2003, 06:52
a tricky one... just giving a shot though... hundrets place 100 + tens place 90 and units 90 == 280.. not too sure still...
Manager
Joined: 26 Aug 2003
Posts: 233
Location: United States
Followers: 1

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

### Show Tags

29 Sep 2003, 08:51
I have this formula I ended up deriving after encountering couple of problems like this one, here it goes:

Setp 1: Make places for as many number of digits as the number of zero's after 1.
Setp 2: The first digit is the number of zeros after 1.
Setp 3: Then rest of the digits are zero.
Setp 4: Add one to this number if your upper range number is included in the count.

So... for this problem

Step 1: _ _ _
Step 2: 3 _ _
Setp 3: 3 0 0
Setp 4: 3 0 1

So total number of zero's between 1 and 1000, inclusive, is 301.

This count formula also works for all other digits except you don't do the Step #4. Of course, this formula has certain rules if your range doesn't end at a number that has 1 and tailing zeros. Which I'll mention some other time when I have more time at hand.

----------

Another way.

(# of zeros) * (Upper Range/10) [+ 1] = total number of 1's in the range
where [+ 1] is optional depending on your upper limit.

In this case:
3 * (1000/10) + 1 = 301
SVP
Joined: 03 Feb 2003
Posts: 1603
Followers: 8

Kudos [?]: 181 [0], given: 0

### Show Tags

03 Oct 2003, 04:11
consider one-digit numbers: the only 1

consider two-digit numbers: X1 (eight such numbers), 1X (nine) and 11. In total there are 8+9+2=19

consider three-digit numbers: XX1 (8*9=72), X1X (8*9=72), 1XX (9*9=81), 11X (9*2=18), 1X1 (9*2=18), X11 (8*2=16), and 111 (3). Total:72+72+81+18+18+16+3=280

1000 gives one 1.

Overall: 1+19+280+1=301
[#permalink] 03 Oct 2003, 04:11
Display posts from previous: Sort by

# One writes a list of numbers from 1 to 1000. How many ones

 post reply Question banks Downloads My Bookmarks Reviews Important topics

 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®.