View Single Post
Old 2006 May 11th, 09:06 PM   #41 (permalink)
lionheart7
I JUST got here.
 
Join Date: May 2006
Posts: 1
lionheart7 just joined TestMagic.
[quote=almas]
Quote:
Originally Posted by TwinnSplitter
Thanks for these great resources.

My answers to that document are as follows, anybody else who did them let me know what you got:
B
C
A
C

A bag of 10 marbles contains 3 red marbles and 7 blue marbles. If two marbles are selected at random, what is the probability that at least one marble is blue?

D (the way I did this took kind of long, if somebody else could let me know how they did it I'd appreciate it)


(7c1*3c1+7c2)10c2= 42/45=14/15
answer D
= 1 - Probability that both marbles are red
= 1 - (3/10)*(2/9)
= 1 - 6/90
= 1 - 1/15
= 14/15
lionheart7 is offline