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A bag contains 3 red balls, 4 green balls, and 5 yellow balls. If balls are drawn one at a time without replacement, what is the probability that the first yellow ball is drawn on the eighth draw? Express your answer as a common fraction.

 May 22, 2021
 #1
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Here's my  take

 

We  would  have  to draw    all    the  red  and  green balls  in the  first  7 draws

 

The probability of  this  is      (7/12) (6/11) (5/10) ( 4/9) ( 3/8) ( 2/ 7) ( 1/ 6)   =    1/ 792

 

cool cool cool

 May 22, 2021

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