Check GMAT Club Decision Tracker for the Latest School Decision Releases https://gmatclub.com/AppTrack

 It is currently 28 May 2017, 01:18

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 odd three-digit integers greater than 800 are there

 post reply Question banks Downloads My Bookmarks Reviews Important topics
Author Message
Manager
Joined: 12 Feb 2008
Posts: 179
Followers: 1

Kudos [?]: 40 [1] , given: 0

How many odd three-digit integers greater than 800 are there [#permalink]

Show Tags

31 Oct 2008, 08:49
1
KUDOS
This topic is locked. If you want to discuss this question please re-post it in the respective forum.

How many odd three-digit integers greater than 800 are there such that all their digits are different?

Please show your calculations. I will provide the OA.
Current Student
Joined: 24 Oct 2008
Posts: 105
Followers: 2

Kudos [?]: 16 [1] , given: 2

Re: three-digit integers [#permalink]

Show Tags

31 Oct 2008, 11:05
1
KUDOS
That's a tough one. I get 68...
Senior Manager
Joined: 31 Jul 2008
Posts: 296
Followers: 1

Kudos [?]: 49 [0], given: 0

Re: three-digit integers [#permalink]

Show Tags

31 Oct 2008, 11:48
72 for me

the Hundreds digit can be 8,9
Units can be 1,3,5,7,9
middle can be any of the 10

case 1 :

Hundreds digit = 8
Units can be any 5 digits
middle one can be any of the 8 digits apart from 8 & (any one of 1,3,5,7,9)

Total = 8*5=40

case 2 :

Hundreds digit = 9
Units can be any 4 digits (exclude 9)
middle one can be any of the 8 digits apart from 9 & (any one of 1,3,5,7)

Total = 8*4=32

Total no. of ways = 72
Manager
Joined: 11 Apr 2008
Posts: 202
Followers: 2

Kudos [?]: 17 [0], given: 1

Re: three-digit integers [#permalink]

Show Tags

31 Oct 2008, 14:05
From 800-899= Consider the tenth and unit position 1 (8)1 X even X odd= 1x4x5=20
Similarly =(8)1x odd x other odd=1x5x4=20
From 899-999= (9) 1x even x odd=1x5x4=20
Similarly=(9)1x oddx odd= 1x4x3=12 (because 9 is already used in the hundredth position.
So the total number of digits are=20+20+20+12=72
_________________

Nobody dies a virgin, life screws us all.

VP
Joined: 30 Jun 2008
Posts: 1034
Followers: 14

Kudos [?]: 613 [0], given: 1

Re: three-digit integers [#permalink]

Show Tags

01 Nov 2008, 07:56
subarao wrote:
From 800-899= Consider the tenth and unit position 1 (8)1 X even X odd= 1x4x5=20
Similarly =(8)1x odd x other odd=1x5x4=20

From 899-999= (9) 1x even x odd=1x5x4=20
Similarly=(9)1x oddx odd= 1x4x3=12 (because 9 is already used in the hundredth position.
So the total number of digits are=20+20+20+12=72

good one subarao
_________________

"You have to find it. No one else can find it for you." - Bjorn Borg

Re: three-digit integers   [#permalink] 01 Nov 2008, 07:56
Display posts from previous: Sort by

How many odd three-digit integers greater than 800 are there

 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®.