23. Urn 1 contains 5 white and 6 black balls, while urn 2 contains 8 white and 10 black balls. Two balls are randomly selected from urn 1 and are then put in urn 2. If 3 balls are then randomly selected from urn 2, compute the expected number of white balls in the trio.

HINT: Let X1 if the ith white ball initially in urn 1 is one of the three selected, and let X, 0 otherwise. Similarly, let Y, 1 if the ith white ball from urn 2 is one of the three selected, and let Y, 0 otherwise. The number of white balls in the trio can now be written as 5

8

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