CBSE Class 12-science Answered

Event-1 :- First time black ball is drawn and second time also black ball is drawn ( B+B)

probability of selecting black ball first time is 6/10 ; probability of selecting black ball second time is 5/9 ;

probability of not selecting red ball is  , P(B+B) = (6/10) × (5/9) = 1/3

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Event-2 :- First time black ball is drawn and second time red ball is drawn ( B+R)

probability of selecting black ball first time is 6/10 ; probability of selecting red ball second time is 4/9 ;

probability of selecting black ball first and red ball next is  , P(B+R) = (6/10) × (4/9) = 4/15 ;

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Event-3 :- First time red ball is drawn and second time black ball is drawn ( R+B)

probability of selecting red ball first time is 4/10 ; probability of selecting black ball second time is 6/9 ;

probability of selecting red ball first and black ball next is  , P(R+B) = (4/10) × (6/9) = 4/15 ;

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Event-1 :- First time red ball is drawn and second time also red ball is drawn ( R+R )

probability of selecting red ball first time is 4/10 ; probability of selecting red ball second time is 3/9 ;

probability of selecting red ball both time is  , P(R+R) = (4/10) × (3/9) = 2/15

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