问题 解答题

某商店准备从机械厂购进甲、乙两种零件进行销售,若每个甲零件的进价比每个乙种零件的进价少2元,且用80元购进甲种零件的数量与用100元购进乙种零件的数量相同。

(1)求甲、乙两种零件每个的进价分别为多少元?

(2)若该商店本次购进甲种零件的数量比购进乙种零件的数量的3倍还少5个,购进两种零件的总数量不超过95个,将本次购进的甲、乙两种零件全部售出后,可使销售两种零件的销售价格均为12元,则将本次购进的甲、乙两种全部售出后,可使销售两种零件的总利润(利润=售价-进价)超过302元,通过计算求出该商店本次从机械厂购进甲、乙两种零件有几种方案?请你设计出来。

答案

(1)甲种零件进价为8元,乙种零件进价为10元(2)方案一,购进甲种零件67个,乙种零件24个;方案二:购进甲种零件70个,乙种零件25个

(1)设每个乙种零件进价为x元,则每个甲种零件进价为(x-2)元,

依题意得                                                 

 解得                              …………2分

经检验x=10是方程的解,10-2=8                            …………3分

答:甲种零件进价为8元,乙种零件进价为10元              …………4分

(2)设购进乙种零件为y个,则购进甲种零件(3y-5)个,依题意得

                    …………6分

解得                                         …………8分

∵y为整数   ∴y=24或25 ∴共2种方案 

分别是:方案一,购进甲种零件67个,乙种零件24个;       

方案二:购进甲种零件70个,乙种零件25个.  ………10分

(1)设每件乙种商品的进价为x元,则每件甲种商品的进价为(x-2)元,根据题意建立方程求出其解就可以了.

(2)本题中“根据进两种商品的总数量不超过95个”可得出关于数量的不等式,根据“使销售两种商品的总利润(利润=售价-进价)超过302元”可以得出关于利润的不等式,组成不等式组后得出未知数的取值范围,然后根据取值的不同情况,列出不同的方案.

阅读理解

There are many unusual hotels around the world .In Greenland ,there is a hotel made out of ice ,open between December and April every year .In Turkey ,there is a cave hotel with a television ,furniture ,and a bathroom in each room .And in Bolivia ,there is the Salt Palace Hotel .

Thousands of years ago ,the area has the Salt Palace Hotel was a large lake . But over time ,all the water disappeared . Today ,the area has only two small lakes and two salt deserts .

The larger of the two deserts the Uyuni salt desert ,is 12000 square kilometers .During the day ,the desert is bright white because of the salt .There are no roads across the Uyuni desert ,so local people must show guests the way to the hotel .

In the early 1900s ,a man named Juan Quesada built the hotel .He cut big blocks of salt from the desert and used the blocks to build it. Everything in the hotel is made out of salt ;the walls , the roof , the chairs , the tables ,the beds ,and the hotels bar .

The Sun heats the walls and the roof during the day . At night is very cold , but the rooms stay warm . The hotel has twelve rooms . A single room costs 40 dollars a night .and a double room costs 60 dollars .

A sign on the hotels wall tells guests ,Please do not lick 添the walls.

小题1:What is unique about the Salt palace hotel ?

A.Its long history

B.The price of the rooms.

C.The guests that stay there

D.What it is made of小题2:Which sentences about the area around the Salt palace hotel  is  NOT true?

A.It was a lake many years ago .

B.It is white during the day .

C.There are several roads to the hotel.

D.It is more than 10,000 square kilome ters.小题3:Who is Juan Quesada?

A.A hotel guest

B.A guide

C.The hotels owner

D.An expert .小题4:who keeps the rooms warm at night ?

A.Heat from the walls.

B.The desert air ,

C.The sun.

D.The furniture .

单项选择题