问题 解答题

某校有A.B两个餐厅,甲、乙两名学生各自随机选择其中一个餐厅用餐.

(1)甲、乙两名学生在同一餐厅用餐的概率为______;

(2)如果有A、B、C三个餐厅,甲、乙两名学生各自随机选择其中一个餐厅用餐,用树状图或列表法,求甲、乙两名学生在同一餐厅用餐的概率.

(3)若有m个餐厅,10名学生各自随机选择其中一个餐厅用餐,请直接写出10名学生在同一餐厅用餐的概率为______.

答案

(1)共有4种情况,甲乙两人在同一餐厅用餐的情况有2种,

∴甲、乙两名学生在同一餐厅用餐的概率为

1
2

故答案为

1
2

(2)共有9种情况,甲乙两人在同一餐厅用餐的情况有3种,

∴甲、乙两名学生在同一餐厅用餐的概率为

1
3
;(3)共有m个餐厅,每个同学都有m个选择,那么10个同学的就餐将有m10种情况,每个餐厅都可能出现有10个同学吃饭,所以可能在一个餐厅吃饭的情况数有

m种情况,所以10名学生在同一餐厅用餐的概率为m÷m10=

1
m9
,故答案为
1
m9

选择题
阅读理解

Online grocery shopping was counted as the next great innovation to make our lives easier. In China more than 3,000 websites offer the service, but none have turned a profit.

Xiang Nian has had a hard day at the office but at least she can skip the trip to the grocery store. A text message on her phone lets her know the order she placed earlier in the day has been delivered to a locker outside her apartment.

"It’s really convenient for an office worker like me. My fresh products are waiting for me when I get home and can start cooking. No need to go to the supermarket any more," Xiang says.

One of the largest online supermarkets in Wuhan is Just-easy Fresh Produce. Over the past 3 years, the company has developed its online retail grocery business by guaranteeing fresh produce and an innovative delivery system. They've installed thousands of lockers in communitieshttp:// / around downtown Wuhan.

"We get an average of 8,000 orders per day. That's the most in China, I'm proud of it. We have placed over 20 thousand lockers in more than half of the communities in Wuhan and we plan to expand to all of them. Many e-commerce giants, like Taobao, are talking about cooperation with us," Jie Xiaofeng, manager of Wuhan Just-easy Agricultural Science & Technology Co., says.

While Just-easy may have thousands of customers, a staff of almost 300 and 40 delivery trucks, it's still operating in the red.

"There are over 3,000 companies selling fresh products online in China. But none is making a profit. It will take them at least 3 years before they make a profit. The major challenge is the cost of delivery. But they do have many advantages. The price of their goods is lower than the supermarkets," professor He Dehua at Huazhong Agricultural University, says.

A number of China's e-commerce giants are making moves into online grocery sales, with Taobao opening an online platform it calls "Cainiao". And traditional retailers(零售店) including Wal-Mart and Carrefour are also looking to start selling their produce online.

Many big B2C e-commerce players usually take fresh farm produce as the last category to add to their offerings. But now more and more large businesses have set their eyes on the industry. They want to prove the fresh food market is definitely suited to online sales.

小题1:What is the main idea of the passage?

A.The online grocery shopping is making our life easier.

B.Just-easy Fresh Produce is a pioneer of the online retail grocery business.

C.Conventional retailers are facing challenges.

D.None of the online grocery supermarkets has made a profit.小题2:The underlined part “it's still operating in the red” probably means _______.

A.the present situation of the company makes them angry

B.the company is not making a profit

C.the company is very popular with customers

D.the staff of the company are aggressive小题3:What can we learn from the last two paragraphs?

A.The fresh food market is definitely suited to online sales.

B.Fresh farm produce is the last category that people will buy online.

C.Online grocery sales have drawn the attention of e-commerce giants.

D.Traditional retailers choose to sell their produce on Cainiao.小题4:What’s the author’s attitude towards online grocery shopping?

A.Pessimistic.

B.Indifferent.

C.Objective.

D.Supportive.