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

It is currently 25 May 2013, 10:32
Customize  |  Hide

Probability Q

  Question banks Downloads My Bookmarks Reviews  
Author Message
TAGS:
Intern
Intern
Joined: 16 Apr 2005
Posts: 18
Followers: 0

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

Probability Q [#permalink] New post 16 Apr 2005, 20:53
Hey Guys,

Know the Q's below are probability based .. But no clue how to go about solving them. If anyone could explain, that would be great! Thanks.

A nationwide survey showed that 65% of all children in the United States dislike eating vegetables. If 4 children are chosen at random, what is the probability that all 4 dislike eating vegetables? (Round your answer to the nearest percent)

a. 18%
b. 260%
c. 2%
d. none of the above

In New York state, 48% of all teenagers own a skateboard and 39% of all teenagers own a skateboard and roller blades. What is the probablity that a teenager owns roller blades given that the teenager owns a skateboard?

a. 87%
b. 81%
c. 123%
d. none of the above
Senior Manager
Senior Manager
Joined: 15 Mar 2005
Posts: 432
Location: Phoenix
Followers: 1

Kudos [?]: 7 [0], given: 0

GMAT Tests User
Re: Probability Q [#permalink] New post 16 Apr 2005, 23:40
gix wrote:
Hey Guys,

Know the Q's below are probability based .. But no clue how to go about solving them. If anyone could explain, that would be great! Thanks.

A nationwide survey showed that 65% of all children in the United States dislike eating vegetables. If 4 children are chosen at random, what is the probability that all 4 dislike eating vegetables? (Round your answer to the nearest percent)

a. 18%
b. 260%
c. 2%
d. none of the above

In New York state, 48% of all teenagers own a skateboard and 39% of all teenagers own a skateboard and roller blades. What is the probablity that a teenager owns roller blades given that the teenager owns a skateboard?

a. 87%
b. 81%
c. 123%
d. none of the above


(1) The probability of a kid's disliking eating vegetables = 13/20.
The probability of 4 kids out of 4 disliking vegetables = (13/20)^4
= 0.178 = 18%
(D).

(2) Out of a sample 100 teeangers, 48 own skateboards, and of them 39 own roller blades as well. Thus for a given teenager having a skateboard, the probability of having roller blades = 39/48 = 13/16 = 0.712 = 71%
(D).

Please post your solutions too.

Thanks.
_________________

Who says elephants can't dance?

Director
Director
Joined: 19 Feb 2005
Posts: 508
Location: Milan Italy
Followers: 1

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

GMAT Tests User
 [#permalink] New post 17 Apr 2005, 02:44
I reached the same solutions for these problems.

(1) 65/100*65/100*65/100*65/100

(2) P(A|B)=P(A)/P(B) (when they are indipendent events)
Intern
Intern
Joined: 16 Apr 2005
Posts: 18
Followers: 0

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

 [#permalink] New post 17 Apr 2005, 09:57
Yes the answers are correct!

For the second one, your math actually works out to 81% and not 71% making the correct answer B.


Thanks very much!
Manager
Manager
Joined: 13 Oct 2004
Posts: 246
Followers: 1

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

GMAT Tests User
 [#permalink] New post 17 Apr 2005, 10:01
1. A
2. B as 39/48 = 81%
  [#permalink] 17 Apr 2005, 10:01
    Similar topics Author Replies Last post
Similar
Topics:
New posts probability Q lastochka 4 31 May 2004, 13:24
New posts probability Q oops 6 16 Apr 2007, 23:27
New posts Probability Q yuefei 4 15 Oct 2007, 12:32
New posts probability Q elinka 1 27 Nov 2009, 12:27
Moved topic 6 EXPERTS_POSTS_IN_THIS_TOPIC In how many different ways can the letters A, A, B tania 19 24 Dec 2009, 16:17
Display posts from previous: Sort by

Probability Q

  Question banks Downloads My Bookmarks Reviews  


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®.