某宾馆有30个房间供游客住宿，当每个房间的房价为每天160元时，房间会全部住满。当每个房间每天的房价每增加10元时，就会有一个房间空闲。宾馆需对游客居住的每个房间每天支出20元的各种费用。根据规定，每个房间每天的房价不得高于260元。
设每个房间的房价每天增加x元（x为10的整数倍）。
（1）设一天订住的房间数为y，直接写出y与x的函数关系式及自变量x的取值范围；
（2）设宾馆一天的利润为w元，求w与x的函数关系式；
（3）一天订住多少个房间时，宾馆的利润最大？最大利润是多少元？

    Chores weren't popular at my house. My children didn't like to do chores. They always saw me do chores, but they hardly ever helped me do them.

    A year ago, I made a game called "The Endless Chore Game". It's really great. Here show the game works.

    I make a card with forty squares（方框）, and I writea different chore on each square. These chores can be easy and interesting like making dessert. Then my family roll the dice（骰子）to decide what chores we have to do. The card also has a few squares with fun things, like watching TV and singing. If you're lucky, you can watch TV when the others are doing the chores.

    My son likes the game very much. He goes to the kitchen happily every morning to do the game. It's really a good way to make my children do chores. You can have a try if you have the same problem as me.