Please solve Q. No. 1

Dear Student, your question seems to be incomplete. Assuming your question to be " Bag (A)  has 4 red and 5 black balls. Second bag (B) has 3 red and 7 black balls. One ball is drawn bag A and two from bag B. Find the probability that out of 3 balls drawn,two are black and one is red?"

Solution)
2 black and one red ball can be drawn in two mutually exclusive ways.1) Drawing one black ball from bagA and two balls from bag B out of which one isblack and other is red.2) Drawing one red ball from bag A two black balls from bag B.Thus, if we defone the following events:E1=Drawing a black ball from bag AE2=Drawing one red and one black ball from bag BE3=Drawing one red ball from bag AE4=Drawing two black balss from bag B.Then P(E1)=59,P(E2)=3C1×7C110C2=2145,P(E3)=49,P(E4)=7C210C2=715Now,P(Two black balls and one red ball)=P1 black from bag A and one red and one black ball from bag Bor one red from bag A and 2 black from bag B=P(I or II)=P(III)=PE1E2E3E4=PE1E2+PE3E4=P(E1)P(E2)+P(E3)P(E4)=59×2145+49×715=63135=715
Regards!

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