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, 10:07
Customize  |  Hide

Search
Register
New posts
Unanswered

In a raffle in which 200 tickets are sold, there are 3

  Question banks Downloads My Bookmarks Reviews  
  Oldest Best Reply
Search for:
 
Print view
First unread post
Author Message
TAGS:
Intern
Intern
Joined: 18 Aug 2005
Posts: 17
Followers: 0

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

In a raffle in which 200 tickets are sold, there are 3 [#permalink] New post 06 Nov 2005, 18:15
In a raffle in which 200 tickets are sold, there are 3 prizes - first prize of $100, second prize of $50, third prize of $30. A girl has one ticket in the raffle. What is the probability that she wins

(a) a prize,
(b) at least $50.
Current Student
User avatar
Joined: 23 Oct 2005
Posts: 244
Schools: Cranfield SOM
Followers: 2

Kudos [?]: 13 [0], given: 2

GMAT Tests User
Re: Probability [#permalink] New post 06 Nov 2005, 18:35
sandman wrote:
In a raffle in which 200 tickets are sold, there are 3 prizes - first prize of $100, second prize of $50, third prize of $30. A girl has one ticket in the raffle. What is the probability that she wins

(a) a prize,
(b) at least $50.


I really suck at Probaility and counting. But here's my try.

1) Atleast a prize:

P(First) = 1/200 (she has one ticket, hence the probability of her winning the prize is 1 in 200)
P (Second) = 199/200 * 1/199 (Probability of not winning first * Probability that she wins 2nd)
P(third) = 199 / 200 * 198/199 * 1/198 (Prob of not winnning first and second * prob of winning third)

P (at least one) = P(First) + P(second) + P(Third)

2) Winning 3rd - P(Third) from above.

Am I right?
Intern
Intern
Joined: 18 Aug 2005
Posts: 17
Followers: 0

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

 [#permalink] New post 06 Nov 2005, 19:07
Part a.
P(girl wins atleast 1 prize) = 1 – P(girl wins no prizes)

P(no prizes) = P(no first prize) x P(no second prize) x P(no third prize)
= 199/200 x 198/199 x 197/198
= 197/200

So, P(girl wins atleast 1 prize) = 1 – 197/200
= 3/200

Part b.
P(atleast $50) = P(wins first prize) OR P(wins second prize)

P(wins first prize) = 1/200

P(winning second prize) = P(not winning first) AND P(she wins 2nd)
= 199/200 x 1/199
= 1/200

So, P(atleast $50) = 1/200 + 1/200
= 1/100
  [#permalink] 06 Nov 2005, 19:07
    Similar topics Author Replies Last post
Similar
Topics:
 New posts A man buys 5 tickets in a raffle in which 100 tickets are schumacher 1 04 Jan 2005, 13:01
New posts An a small raffle, there are only 2 prizes, and 30 tickets sandman 7 06 Nov 2005, 18:05
New posts DS: Raffle Tickets - GMATPrep tennis_ball 8 24 Nov 2006, 22:36
New posts Raffle tickets.... milind1979 2 27 Apr 2009, 21:06
New posts EXPERTS_POSTS_IN_THIS_TOPIC Raffle tickets GMATD11 3 20 Feb 2011, 09:26
Display posts from previous: Sort by

In a raffle in which 200 tickets are sold, there are 3

  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