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 May 22, 2017
 #1
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Probability  that first is black  = [ 12 black pens] / [ 30 Total Pens]  =  12 / 30  =  2/ 5

 

Probability that second is red  =  [  5 red pens ]  /  [ 29 Remaining Pens]  =  5 / 29

 

So.....the total probability  is    ( 2 / 5) * ( 5 / 29)   

 

Swap  denominators   = (2/29) ( 5 / 5 )   = ( 2 / 29 )  * ( 1 )  =

 

2 / 29

 

 

cool cool cool

 May 22, 2017

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