BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

Simple problem or Tough problem ???

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
User avatar
Legendary Member
Posts: 1665
Joined: Thu Nov 03, 2011 7:04 pm
Thanked: 165 times
Followed by:70 members

Simple problem or Tough problem ???

by karthikpandian19 » Tue Jan 10, 2012 12:14 am
Jim and Renee will play one game of Rock, Paper, Scissors. In this game, each will select and show a hand sign for one of the three items. Rock beats Scissors, Scissors beat Paper, and Paper beats Rock. Assuming that both Jim and Renee have an equal chance of choosing any one of the hand signs, what is the probability that Jim will win?

5/6

2/3

1/2

5/12

1/3

Is this a simple problem or tough one? Sometimes i get carried away with the info tht the sum is tough
Top
Source: — Problem Solving |
User avatar
Legendary Member
Posts: 626
Joined: Fri Dec 23, 2011 2:50 am
Location: Ahmedabad
Thanked: 31 times
Followed by:10 members

by ronnie1985 » Tue Jan 10, 2012 12:25 am
Jim can win only if one of the following conditions are met:-
(1) Jim = Rock, Reeve = Scissor
(2) Jim = Scissor, Reeve = Paper
(3) Jim = Paper, reeve = Rock
The probability is 1/9+1/9+1/9 = 1/3
Follow your passion, Success as perceived by others shall follow you
Top
Legendary Member
Posts: 966
Joined: Sat Jan 02, 2010 8:06 am
Thanked: 230 times
Followed by:21 members

by shankar.ashwin » Tue Jan 10, 2012 12:25 am
Dont get tempted writing various probability cases and complicate things.

3 results are possible : a win, a tie or losing.

P(A win) = Favorable/total = [spoiler]1/3[/spoiler]
Top
Legendary Member
Posts: 1084
Joined: Fri Apr 15, 2011 2:33 pm
Thanked: 158 times
Followed by:21 members

by pemdas » Mon Jan 23, 2012 9:42 pm
shankar.ashwin wrote:Dont get tempted writing various probability cases and complicate things.

3 results are possible : a win, a tie or losing.

P(A win) = Favorable/total = [spoiler]1/3[/spoiler]
you attempt to use binomial probability when P(success)=1/2 and luckily the odds are equal here P(win)=P(loose)=P(tie)
P(a win)=1/3
P(loose)=1/3
P(tie)=1/3

in all other cases like four or more hand signs when P(loose)>1/3 we get lost by using this method.
Success doesn't come overnight!
Top
User avatar
GMAT Instructor
Posts: 15539
Joined: Tue May 25, 2010 12:04 pm
Location: New York, NY
Thanked: 13060 times
Followed by:1906 members
GMAT Score:790

by GMATGuruNY » Tue Jan 24, 2012 4:18 am
karthikpandian19 wrote:Jim and Renee will play one game of Rock, Paper, Scissors. In this game, each will select and show a hand sign for one of the three items. Rock beats Scissors, Scissors beat Paper, and Paper beats Rock. Assuming that both Jim and Renee have an equal chance of choosing any one of the hand signs, what is the probability that Jim will win?

5/6

2/3

1/2

5/12

1/3

Is this a simple problem or tough one? Sometimes i get carried away with the info tht the sum is tough
Since it is given that Jim and Renee have an equal chance of choosing any one of the hand signs, Renee is irrelevant here: she can select whatever sign she wants.
All that matters is what JIM selects RELATIVE TO RENEE.
He has 3 options: rock, paper, scissors.
Of these 3 options, ONLY ONE will result in a win for Jim.
Thus, P(Jim wins) = 1/3.

The correct answer is E.
Private tutor exclusively for the GMAT and GRE, with over 20 years of experience.
Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.

As a tutor, I don't simply teach you how I would approach problems.
I unlock the best way for YOU to solve problems.

For more information, please email me (Mitch Hunt) at [email protected].
Student Review #1
Student Review #2
Student Review #3
Top
Post new topic Post Reply
• Page 1 of 1