Last visit was: 24 Apr 2024, 02:26 It is currently 24 Apr 2024, 02:26

Close
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
Your Progress

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
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
Close
Request Expert Reply
Confirm Cancel
SORT BY:
Date
User avatar
Manager
Manager
Joined: 13 Mar 2009
Posts: 116
Own Kudos [?]: 1649 [4]
Given Kudos: 60
GMAT 2: 680  Q48  V35 GMAT 3: 710  Q47  V41
Send PM
Most Helpful Reply
User avatar
Manager
Manager
Joined: 10 Aug 2009
Posts: 58
Own Kudos [?]: 99 [5]
Given Kudos: 10
Send PM
General Discussion
User avatar
Manager
Manager
Joined: 14 Aug 2009
Posts: 50
Own Kudos [?]: 148 [0]
Given Kudos: 13
Send PM
User avatar
Manager
Manager
Joined: 13 Mar 2009
Posts: 116
Own Kudos [?]: 1649 [0]
Given Kudos: 60
GMAT 2: 680  Q48  V35 GMAT 3: 710  Q47  V41
Send PM
Re: High Caliber Probability [#permalink]
flyingbunny wrote:
1) if he gets a even ball, he loses
2) if he gets a odd ball, (this number) + (the number he drew in the first time)= even


Odd + Even = Odd. The player is in the game.
Odd + Odd = Even. The player loses.

The problem is still solvable. :)
User avatar
Manager
Manager
Joined: 14 Aug 2009
Posts: 50
Own Kudos [?]: 148 [0]
Given Kudos: 13
Send PM
Re: High Caliber Probability [#permalink]
DenisSh wrote:
A lottery game works as follows: The player draws a numbered ball at random from an urn containing five balls numbered 1, 2, 3, 4, and 5. If the number on the ball is even, the player loses the game and receives no points; if the number on the ball is odd, the player receives the number of points indicated on the ball. Afterward, he or she replaces the ball in the urn and draws again. On each subsequent turn, the player loses the game if the total of the numbers becomes even, and gets another turn (after receiving the number of points indicated on the ball and then replacing the ball in the urn) each time the total remains odd.

(a) What is the probability that the player loses the game on the third turn?

OA
\(\frac{18}{125}\)


If you can solve that question, then try even harder one:

(b) What is the probability that the player accumulates exactly 7 points and then loses on the next turn?

OA
\(\frac{198}{3,125}\)


The player can't draw any even numbers at any time? or this rule only applies to the first draw?
User avatar
Manager
Manager
Joined: 10 Aug 2009
Posts: 58
Own Kudos [?]: 99 [1]
Given Kudos: 10
Send PM
Re: High Caliber Probability [#permalink]
1
Kudos
Flyingbunny,
Since these are the rules of the game, there is a certain sequence of events.
Here is how I understand the rules.
A player draws a ball (first ball). If the first ball is even, a player is out of the game but puts the ball back.
If a player draws an odd ball, he gets his points, puts a ball back and gets another turn. And since the second draw, he has to watch out for the sum of his points not to be even, meaning he has to draw only even numbers, starting from his second draw...if at any turn (after the 1st) he draws an odd ball he will be out of the game...
My solution was based on this interpretation of rules...
User avatar
Manager
Manager
Joined: 13 Mar 2009
Posts: 116
Own Kudos [?]: 1649 [0]
Given Kudos: 60
GMAT 2: 680  Q48  V35 GMAT 3: 710  Q47  V41
Send PM
Re: High Caliber Probability [#permalink]
LenaA wrote:
1) I got ...


Yes, you are right. Perhaps the most challenging thing is to realize how to interpret rules and convert them into Odd & Even sequences. :)
User avatar
Intern
Intern
Joined: 14 Aug 2009
Posts: 5
Own Kudos [?]: 6 [0]
Given Kudos: 18
Send PM
Re: High Caliber Probability [#permalink]
the question is so twisted
avatar
Intern
Intern
Joined: 25 Nov 2009
Posts: 10
Own Kudos [?]: 9 [0]
Given Kudos: 4
Location: San Francisco
Schools:Wharton West eMBA, Haas EW, Haas eMBA
 Q48  V46
Send PM
Re: High Caliber Probability [#permalink]
half the GMAT is paying attention to the wording. i think it's worded clearly. 1st part is very easy. 2nd . . . not so much.
Manager
Manager
Joined: 15 Nov 2006
Affiliations: SPG
Posts: 232
Own Kudos [?]: 3136 [3]
Given Kudos: 34
Send PM
Re: High Caliber Probability [#permalink]
2
Kudos
1
Bookmarks
a) to lose on the 3rd turn the sequence would be Odd-Even-Odd (OEO).
the probability of getting OEO = \(\frac{3}{5}*\frac{2}{5}*\frac{3}{5} = \frac{18}{125}\)

b) the player will lose after getting a 2nd Odd.

O---E---E---E
1---2---2---2---Odd = \(\frac{1}{5^4}*\frac{3}{5} = \frac{3}{5^5}\)

1---2---4-------Odd = \(\frac{1}{5^3}*\frac{3}{5} = \frac{3}{5^4} = \frac{3*5}{5^5}\)

1---4---2-------Odd = \(\frac{1}{5^3}*\frac{3}{5} = \frac{3}{5^4} = \frac{3*5}{5^5}\)

3---2---2-------Odd = \(\frac{1}{5^3}*\frac{3}{5} = \frac{3}{5^4} = \frac{3*5}{5^5}\)

3---4-----------Odd = \(\frac{1}{5^2}*\frac{3}{5} = \frac{3}{5^3} = \frac{3*5^2}{5^5}\)

5---2-----------Odd = \(\frac{1}{5^2}*\frac{3}{5} = \frac{3}{5^3} = \frac{3*5^2}{5^5}\)

total probability = \(\frac{3}{5^5} + 3*\frac{3*5}{5^5} + 2*\frac{3*5^2}{5^5} = \frac{198}{3125}\)

User avatar
Intern
Intern
Joined: 14 Dec 2011
Posts: 48
Own Kudos [?]: 335 [0]
Given Kudos: 24
GMAT 1: 630 Q48 V29
GMAT 2: 690 Q48 V37
Send PM
Re: High Caliber Probability [#permalink]
I normally hate probability question, but this one was really easy:

3/5 * 2/5 * 2/5 = 18/125
avatar
Intern
Intern
Joined: 08 Oct 2013
Status:At the end all are winners, Some just take a little more time to win.
Posts: 7
Own Kudos [?]: 11 [0]
Given Kudos: 45
Location: India
Concentration: Finance, Accounting
GMAT Date: 11-20-2013
GPA: 3.97
WE:Consulting (Computer Software)
Send PM
Re: High Caliber Probability [#permalink]
Impenetrable wrote:
I normally hate probability question, but this one was really easy:

3/5 * 2/5 * 2/5 = 18/125



Guess u should continue hating it :( Coz the product given by you above is equating to 12/125; not 18/125
User avatar
Manager
Manager
Joined: 03 Jan 2013
Posts: 182
Own Kudos [?]: 40 [0]
Given Kudos: 0
Location: United States
Concentration: Finance, Entrepreneurship
GMAT 1: 750 Q48 V46
GPA: 3.02
WE:Engineering (Other)
Send PM
Re: A lottery game works as follows: The player draws a numbered [#permalink]
FIRST QUESTION

Here's my notes from reading the problem:

Five balls numbered 1,2,3,4,5
Round 1: Player loses on even, player gets points on odd
Round 2-inf: Player loses on even point total, keeps going on odd

FIND: Prob LOSE on Round 3 (Win 1, Win 2, Lose 3)

Here's my solving logic:

Round 1
Lose: 2/5 chance (two even numbers, 2 and 4)
Win: 3/5 chance
End of round point total: 1, 3 or 5

Round 2
Since point total is odd, if the player draws an odd they will lose, as it will make their point total even.
Lose: 3/5 chance (three odd numbers, 1,3 and 5)
Win: 2/5 chance
End of round point total: 1, 3 or 5 plus 2 or 4

Round 3
Again, since point total must be odd, they have to draw an odd to lose.
Lose: 3/5 chance
Win: 2/5 chance

So the probability that the player loses on the third turn is the probability of winning the first two rounds and losing the third:

P(W1) * P(W2) * P(L3)
(3/5)*(2/5)*(3/5) = 18/125

Can come back for second question.
GMAT Club Bot
Re: A lottery game works as follows: The player draws a numbered [#permalink]
Moderators:
Math Expert
92893 posts
Senior Moderator - Masters Forum
3137 posts

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne