怀疑elements of information上有道错题

elements of information theory 第一版 第二章 第8道习题
8. World Series. The World Series is a seven-game series that terminates as soonas either team wins four games. Let X be the random variable that represents the outcome of a World Series between teams A and B; possible values of X are AAAA,BABABAB, and BBBAAAA. Let Y be the number of games played, which ranges from 4 to 7. Assuming that A and B are equally matched and that the games are independent, calculate H(X), H(Y ), H(Y |X), and H(X|Y ).
附件是习题解答。
我觉得游戏的结果和玩的次数的熵应该一样才对。
这道题出得实在不好。大家帮忙判断下。

哦，我知道我错了。游戏结果是把每次的结果单独的来看。
而游戏的次数是把比如4次的所有可能结果看成一个整体来看。