【简答题】We learn from the text that raccoons _ . [ A] only come out at night [ B] often visit people ' s houses [ C] like to find food in rubbish cans [ D ] like to live with people in winter
【简答题】某加油站替公共汽车站代营出租汽车业务,每出租一辆汽车,可从出租公司得到3元.因代营业务,每天加油站要多付给职工服务费60元.设每天出租汽车数X是一个随机变量,它的概率分布如下: X 10 20 30 40 p i 0.15 0.25 0.45 0.15 求因代营业务得到的收入大于当天的额外支出费用的概率.