Questions 22 to 25 are based on the conversation you have just heard.

A．Some friends and relatives that she had no time to visit before.

B．The closest friends and relatives.

C．The friends and relatives that helped her a lot.

D．Some friends and relatives that would get upset if she doesn’t visit.

一个口袋中装有n个红球（n≥5且n∈N）和5个白球，一次摸奖从中摸两个球，两个球颜色不同则为中奖．

（Ⅰ）试用n表示一次摸奖中奖的概率p；

（Ⅱ）若n=5，求三次摸奖（每次摸奖后放回）恰有一次中奖的概率；

（Ⅲ） 记三次摸奖（每次摸奖后放回）恰有一次中奖的概率为P．当n取多少时，P最大？