Question

A bag contains 2 white and 4 black balls. Another bag contains 5 white

and 7 black balls. A ball is transformed from first bag to second bag. Then

a ball is drawn from second bag. Find the probability that it will be white.​

Answer 1

A= Event that white ball transferred

B= Event that black ball transferred

C= Event that ball drawn from secondary bag is white

⇒P ( ball drawn is white ) =P ( white ball transferred ) P ( Ball drawn white ) +P ( black ball transferred ) ×P ( ball drawn white )

=

9

4

×

14

7

+

9

5

×

14

6

=

126

28+30

=

126

58

Hence, the answer is

126

58

.