问题 解答题

星空电视台组织篮球技能大赛,每名选手都要进行运球、传球、投篮三项比赛,每个选手在各项比赛中获得合格与不合格的机会相等,且互不影响。现有A、B、C、D、E、F六位选手参加比赛,电视台根据比赛成绩对前2名进行表彰奖励,

(Ⅰ)求A 至少获得一个合格的概率;

(Ⅱ)求A与B只有一个受到表彰奖励的概率。

答案

解:(Ⅰ)记A运球,传球,投篮合格分别记为,不合格为

则A参赛的所有可能的结果为

共8种,

由上可知至少获得一个合格对应的可能结果为7种,

所以至少获得一个合格的概率为

(Ⅱ)所有受到表彰奖励可能的结果为

个,

只有一个受到表彰奖励的结果为

共8种,

只有一个受到表彰奖励的概率为

阅读理解

阅读理解

     In Britain you're allowed to drive a car when you're seventeen.You have to get a special two-year

driving license before you start.When you're learning,  someone with full license always has to be in the

car with you. You don't have to go to a driving school --a friend can teach you. The person with you

isn't allowed to take money for the lesson unless he's got a teacher's license.

    Before you're allowed to have a full license, you have to take a driving test. You can take a test in

your own car, but it has to be fit for the road. In the test, you have to drive round for half an hour and

then answer a few questions. If you don't pass the test, you're allowed to take it again a few weeks later

if you want to.  In 1970, a woman passed her fortieth test after 212 driving lessons!    ,

    When you've passed your test, you don't have to take it again, and you're allowed to go on driving

as long as (只要) you like, if you're healthy.  Britain's oldest driver was a man who drove in 1974 at

the age of 100.

     Before 1904, everyone was allowed to drive, even children. Then from 1904 car drivers had to have

a license.  But they didn't have to take a test until 1935. In the early days of car driving, before 1978,

cars weren't allowed to go faster than four miles an hour, and someone had to lead the car with a red

flag.

1. Which of the following is NOT necessary for a young man who wants to drive a car alone?

A.  He has to pass a driving test to get a full license.

B. He has to learn to drive in a driving school.

C. He has to get a special two-year driving license.

D. He has to reach the age of 17.

2. A person can't take money for driving lessons unless he            

A. has a full license and a teacher's license

B. has a driving school

C. is good at driving

D. has learned to drive in a driving school

3. In the driving test, one ______ .           

A. must drive his own car

B. has to do some test papers

C. is usually asked to drive on roads for half an hour

D. should have 212 driving lessons

4. The car drivers began to take a driving test in______.        

A. 1878                

B. 1904

C. 1935                

D. 1970

5. The best title for the passage is ______.          

A. Britain Car Drivers

B. Young Men's Driving Licenses

C. Tests for British People

D. Driving License in Britain

单项选择题