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

Redeem

Atleast one blue marble

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Source: — Problem Solving |
Master | Next Rank: 500 Posts
Posts: 186
Joined: Fri Jan 16, 2009 4:57 am
Thanked: 7 times
GMAT Score:720

by gmat_dest » Mon Aug 03, 2009 9:08 am
Probability of at least one blue = 1 - Probability of all red

Probability of both red = 3/10 * 2/9 = 1/15

So, probability of at least one blue = 14/15.
Top
Legendary Member
Posts: 1578
Joined: Sun Dec 28, 2008 1:49 am
Thanked: 82 times
Followed by:9 members
GMAT Score:720

by maihuna » Mon Aug 03, 2009 9:11 am
No marble is blue means both are red: = 3/10*2/9 = 1/15

So at least one blue = 1-1/15 = 14/15
Charged up again to beat the beast :)
Top
Post new topic Post Reply
• Page 1 of 1