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

 It is currently 27 Mar 2015, 21:23

### 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 four digit integers do not contain any digits other

Author Message
TAGS:
CEO
Joined: 21 Jan 2007
Posts: 2766
Location: New York City
Followers: 9

Kudos [?]: 331 [0], given: 4

How many four digit integers do not contain any digits other [#permalink]  15 Nov 2007, 06:50
How many four digit integers do not contain any digits other than 1 or 0 and are such that the sum of the first two digits equals the sum of the last two digits?

3
4
8
10
12

Director
Joined: 13 Dec 2006
Posts: 521
Location: Indonesia
Followers: 6

Kudos [?]: 102 [0], given: 0

1001, 1010, 1111

Amar
Director
Joined: 30 Nov 2006
Posts: 592
Location: Kuwait
Followers: 12

Kudos [?]: 167 [0], given: 0

1111
1010
0101
1001
0110
0000

Total = 8

SVP
Joined: 29 Aug 2007
Posts: 2497
Followers: 57

Kudos [?]: 551 [0], given: 19

Mishari wrote:
1111
1010
0101
1001
0110
0000

Total = 8

A. there are only 6, not 8, possibilities in your solutions and number/integers with 0 at the begaining are not considered 4 digit integers.

1001, 1010 and 1111 are the solutions.
CEO
Joined: 21 Jan 2007
Posts: 2766
Location: New York City
Followers: 9

Kudos [?]: 331 [0], given: 4

GMAT TIGER wrote:
Mishari wrote:
1111
1010
0101
1001
0110
0000

Total = 8

A. there are only 6, not 8, possibilities in your solutions and number/integers with 0 at the begaining are not considered 4 digit integers.

1001, 1010 and 1111 are the solutions.

0 cannot be the 1st digit in an integer.
OA is A
Director
Joined: 01 May 2007
Posts: 794
Followers: 1

Kudos [?]: 115 [0], given: 0

Concur 3. Integers cannot start with 0 and also 0000 is not a integer. All the #s must start with 1 in this case.
Intern
Joined: 01 Nov 2007
Posts: 4
Followers: 0

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

yeah rgt...

when the first digitis fixed left is three places to be filled....hundreds..tens and units.....

..so for the two numbers 1 and 0...

if hundres is filled by 1...then units and tens both should have a 1.....so 1 way....

if hundreds is filled by zero....then units and tens either one can have 1 and the other zero....so two ways.....

so totally three ways.....
Similar topics Replies Last post
Similar
Topics:
How many four digit numbers have no repeat digits, do not contain zero 0 13 Mar 2015, 10:25
6 How many four digit numbers have no repeat digits, do not co 6 04 Nov 2013, 10:45
How many 4 digit nos that do not contain the digits 3 or 6 a 1 02 Feb 2012, 03:46
6 How many four-digit odd numbers do not use any digit more than once? 13 09 Jun 2009, 07:31
How many four-digit numbers that do not contain the digits 3 5 17 Jan 2006, 17:09
Display posts from previous: Sort by