Find all School-related info fast with the new School-Specific MBA Forum
Learn more about the recent changes... close

It is currently 19 May 2013, 19:14
Customize  |  Hide

Search
Register
New posts
Unanswered

If 4 whole numbers taken at random are multiplied together,

  Question banks Downloads My Bookmarks Reviews  
  Oldest Best Reply
Search for:
 
Print view
First unread post
Author Message
TAGS:
Manager
Manager
Joined: 24 Jan 2004
Posts: 87
Location: Valsad
Followers: 1

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

If 4 whole numbers taken at random are multiplied together, [#permalink] New post 04 Jun 2004, 21:08
If 4 whole numbers taken at random are multiplied together, what is the probability that the last digit in the product is 1,3,7 or 9?
_________________

Mayur

Senior Manager
Senior Manager
Joined: 02 Mar 2004
Posts: 372
Location: There
Followers: 1

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

GMAT Tests User
Re: Probability [#permalink] New post 04 Jun 2004, 21:33
abcd = 1, 3, 7, 9 (10)
or a, b, c, d <> 5 (10)

Answer = 4^4/10^4 = 16/625
Manager
Manager
Joined: 24 Jan 2004
Posts: 87
Location: Valsad
Followers: 1

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

 [#permalink] New post 04 Jun 2004, 22:08
hallelujah1234,
Thanks for the solution.
_________________

Mayur

Intern
Intern
Joined: 04 Aug 2003
Posts: 30
Location: Texas
Followers: 0

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

 [#permalink] New post 05 Jun 2004, 10:46
hi helleujah, Can you explain the answer a bit more.

I was wondering a WHOLE NUMBER will include any valid integer and as such you can include a lot of numbers.

so how did you come to 10^4 as the possible combinations in 4 whole numbers. Did you consider only single digit positive whole numbers.
Manager
Manager
Joined: 24 Jan 2004
Posts: 87
Location: Valsad
Followers: 1

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

 [#permalink] New post 06 Jun 2004, 20:03
I reason out as follows: -


Each of the digits 0,1,...,9 occur in 4 ways in the units digit (since we are multiplying 4 whole numbers). so, the total no. of ways = 10^4

Each of the digits 1,3,7,9 can occur in 4^4 ways.

So the prob. = 4^4/10^4.

Correct me if I am wrong.
_________________

Mayur

  [#permalink] 06 Jun 2004, 20:03
    Similar topics Author Replies Last post
Similar
Topics:
 New posts What is the probability that four whole numbers taken at sunniboy007 8 01 Mar 2004, 12:32
New posts Whole Number tarek99 4 19 Nov 2007, 09:10
New posts multiply numbers GMATD11 3 08 Mar 2011, 08:34
New posts 1 EXPERTS_POSTS_IN_THIS_TOPIC Whole numbers? tomcal36dc 2 04 Jun 2011, 14:08
New posts 1 EXPERTS_POSTS_IN_THIS_TOPIC Shortcut for multiply numbers together up to 19 arnivorous 2 29 Jul 2012, 23:01
Display posts from previous: Sort by

If 4 whole numbers taken at random are multiplied together,

  Question banks Downloads My Bookmarks Reviews  
Print view
First unread post

Moderators: Bunuel, VeritasPrepKarishma

Search for:


GMAT Club MBA Forum Home| About| Privacy Policy| Terms and Conditions| GMAT Club Rules| Contact| Sitemap

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®.

Main navigation

GMAT Resources

Partners

MBA Resources

www.gmac.com|www.mba.com