问题 选择题

某旅行社租用A、B两种型号的客车安排900名客人旅行,A、B两种车辆的载客量分别为36人和60人,租金分别为1600元/辆和2400元/辆,旅行社要求租车总数不超过21辆,且B型车不多于A型车7辆.则租金最少为(  )

A.31200元

B.36000元

C.36800元

D.38400元

答案

设分别租用A、B两种型号的客车x辆、y辆,所用的总租金为z元,则

z=1600x+2400y,

其中x、y满足不等式组

36x+60y≥900
x+y≤21
y-x≤7
,(x、y∈N)

∵A型车租金为1600元,可载客36人,∴A型车的人均租金是

1600
36
≈44.4元,

同理可得B型车的人均租金是

2400
60
=40元,

由此可得,租用B型车的成本比租用A型车的成本低

因此,在满足不等式组的情况下尽可能多地租用B型车,可使总租金最低

由此进行验证,可得当x=5、y=12时,可载客36×5+60×12=900人,符合要求

且此时的总租金z=1600×5+2400×12=36800,达到最小值

故选:C

阅读理解

LEEDS, England—A Leeds University psychology professor is teaching a course to help dozens of Britons forgive their enemies.

"The hate we hold within us is a cancer, " Professor Ken Hart said, adding that holding in anger can lead to problems such as high blood pressure and heart disease.

More than 70 people have become members in Hart's first 20-week workshop in London—a course he says is the first of its kind in the world.

These are people who are sick and tired of living with a memory. They realize their bitterness is a poison they think they can pour out, but they end up drinking it themselves, said Canadian- born Hart.

The students meet in groups of eight to ten for a two-hour workshop with an adviser every fortnight.

The course, ending in July, is expected to get rid of the cancer of hate in these people. "People have lots of negative attitudes towards forgiveness," he said, "People confuse forgiveness with forgetting. Forgiveness means changing from a negative attitude to a positive one."

Hart and his team have created instructions to provide the training needed.

"The main idea is to give you guidelines on how to look at various kinds of angers and how they affect you, and how to change your attitudes towards the person you are angry with," said Norman Claringbull, a senior expert on the forgiveness project.

Hart said he believes forgiveness is a skill that can be taught, as these people "want to get free of the past".

小题1:From this passage we know that________.

A.high blood pressure and heart disease are caused by hate

B.high blood pressure can only be cured by psychology professors

C.without hate, people will have less trouble connected with blood and heart

D.people who suffer from blood pressure and heart disease must have many enemies小题2:If you are angry with somebody, you should________.

A.attend Hart’s course

B.never meet him or her any longer

C.persuade him or her to have a positive talk with you

D.treat him or her positively instead of negatively小题3:In Hart's first 20- week workshop, people there can ________.

A.meet their enemies

B.change their attitudes

C.enjoy the professor's teaching

D.learn how to quarrel with others小题4:If you are a member in Hart's workshop, you'll________.

A.meet in eight or ten groups

B.get rid of the illness of cancer

C.attend a gathering twice a month

D.pour out everything stored in your mind小题5:The author wrote this passage in order to________.

A.persuade Britons to go to Hart's workshop

B.tell us the news about Hart's workshop

C.tell us how to run a workshop like Hart's

D.help us to look at various kinds of angers

单项选择题