Zhang San, Li Si, and Wang Wu ride bicycles from A to B. At 8:00 a.m., Zhang San and Li Si start from A together. Zhang San travels 9 kilometers per hour, and Li Si travels 8 kilometers per hour. Kilometers, Wang Wu starts from A at 9:00 am, and Zhang San and Wang Wu arrive at B at 12:00 noon. So what is the time (moment) when Wang Wu catches up with Li Si?
张三、李四、王五骑自行车都从甲地到乙地，上午8时张三、李四两人一起先从甲地出发，张三每小时行9千米，李四每小时行8千米，王五上午9时才从甲地出发，中午12时张三与王五同时到达乙地．那么王五追上李四的时间(时刻)是多少．
<result>11</result>