picks up blue

This topic has expert replies
User avatar
GMAT Instructor
Posts: 3650
Joined: Wed Jan 21, 2009 4:27 am
Location: India
Thanked: 267 times
Followed by:80 members
GMAT Score:760

picks up blue

by sanju09 » Tue Jul 27, 2010 4:57 am
Probability that a player picks up a red ball from a basket containing red, blue and black balls is ¼. What is the probability that the player picks up blue ball?
(1) Probability that the player picks up either red or black ball is 2/3.
(2) Probability that player picks up red or blue ball is 7/12.

[spoiler]Source: writegmat.com[/spoiler]
The mind is everything. What you think you become. -Lord Buddha



Sanjeev K Saxena
Quantitative Instructor
The Princeton Review - Manya Abroad
Lucknow-226001

www.manyagroup.com
Source: — Data Sufficiency |

User avatar
Legendary Member
Posts: 1893
Joined: Sun May 30, 2010 11:48 pm
Thanked: 215 times
Followed by:7 members

by kvcpk » Tue Jul 27, 2010 6:17 am
sanju09 wrote:Probability that a player picks up a red ball from a basket containing red, blue and black balls is ¼. What is the probability that the player picks up blue ball?
(1) Probability that the player picks up either red or black ball is 2/3.
(2) Probability that player picks up red or blue ball is 7/12.

[spoiler]Source: writegmat.com[/spoiler]
P(R) = 1/4
Probability that the player picks up either red or black ball is 2/3.
P(Blue) = 1-p(R)+P(BLACK)
p(R)+P(BLACK) = 2/3
P(BLUE) = 1/3
SUFF
Probability that player picks up red or blue ball is 7/12.
P(Red and BLUE) = P(RED) +P(BLUE) -P(RED OR BLUE)
0 = 1/4+P(BLUE)-7/12
P(BLUE)=4/12 = 1/3
SUFF
pick D

User avatar
Legendary Member
Posts: 748
Joined: Sun Jan 31, 2010 7:54 am
Thanked: 46 times
Followed by:3 members

by outreach » Tue Jul 27, 2010 12:33 pm
D
-------------------------------------
--------------------------------------
General blog
https://amarnaik.wordpress.com
MBA blog
https://amarrnaik.blocked/

Senior | Next Rank: 100 Posts
Posts: 58
Joined: Tue Aug 26, 2008 9:42 am

by ru2008 » Tue Jul 27, 2010 3:50 pm
D is the answer

Senior | Next Rank: 100 Posts
Posts: 58
Joined: Tue Aug 26, 2008 9:42 am

by ru2008 » Tue Jul 27, 2010 3:51 pm
D is the answer