We use cookies to personalise content and advertisements and to analyse access to our website. Furthermore, our partners for online advertising receive pseudonymised information about your use of our website. cookie policy and privacy policy.
 
+0  
 
+2
743
2
avatar+474 

A bin has 8 black balls and 7 white balls. 3 of the balls are drawn at random. What is the probability of drawing 2 of one color and 1 of the other color?

 Sep 26, 2017
 #1
avatar+100439 
+1

 

Number of ways to draw  2 black and 1 white  = C( 8,2) * C(7,1)        (1)

 

Number of ways to draw  1 black and 2 white  = C( 8,1) * C(7,2)       (2)

 

Number   of ways to draw  3 balls from 15  =  C( 15,3)     (3)

 

Total Probability  =   [ (1) + (2) ] / (3)  = 

 

[   C( 8,2) * C(7,1)  + C( 8,1) * C(7,2)  ] / [  C( 15,3) ]  = .8  =  80%  

 

 

cool cool cool

 Sep 26, 2017
 #2
avatar
0

its 4

 Sep 26, 2017

4 Online Users