问题 解答题

某校师生积极为汶川地震灾区捐款,在得知灾区急需账篷后,立即到当地的一家账篷厂采购,帐篷有两种规格:可供3人居住的小账篷,价格每顶160元;可供10人居住的大账篷,价格每顶400元.学校花去捐款96 000元采购这两种帐篷,正好可供2300人临时居住.

(1)求该校采购了多少顶3人小帐篷,多少顶10人大帐篷;

(2)学校现计划租用甲、乙两种型号的卡车共20辆将这批帐篷紧急运往灾区,已知甲型卡车每辆可同时装运4顶小帐篷和11顶大账篷,乙型卡车每辆可同时装运12顶小帐篷和7顶大帐篷.如何安排甲、乙两种卡车可一次性将这批帐篷运往灾区有哪几种方案?

答案

解:(1)设采购了x顶3人小帐篷,y顶10人大帐篷.

由题材意得.解得

答:采购了100顶3人小帐篷,200顶10人大帐篷.

(2)设甲型卡车安排了a辆,则乙型卡车安排了(20﹣a)辆

.解得15≦a≦17.5

∵a为整数

∴a=15,16,17

则20﹣a=5、4、3

答:有3种方案:

①甲型卡车15辆,乙型卡车5辆.

②甲型卡车16辆,乙型卡车4辆.

③甲型卡车17辆,乙型卡车3辆.

选择题
单项选择题

Although there are many skillful Braille readers, thousands of other blind people find it difficult to learn that system. They are thereby shut (1) from the world of books and newspapers, having to (2) on friends to read aloud to them.

A young scientist named Raymond Kurzweil has now designed a computer which is a major (3) in providing aid to the (4) .His machine, Cyclops, has a camera that (5) any page, interprets the print into sounds, and then delivers them orally in a robot-like (6) through a speaker. By pressing the appropriate buttons (7) Cyclops’s keyboard, a blind person can "read" any (8) document in the English language.

This remarkable invention represents a tremendous (9) forward in the education of the handicapped. At present, Cyclops costs $ 50,000. (10) , Mr. Kurzweil and his associates are preparing a smaller (11) improved version that will sell (12) less than half that price. Within a few years, Kurzweil (13) the price range will be low enough for every school and library to (14) one. Michael Hingson, Director of the National Federation for the Blind, hopes that (15) will be able to buy home (16) of Cyclops for the price of a good television set.

Mr. Hingson’s organization purchased five machines and is now testing them in Maryland, Colorado, Iowa, California, and New York. Blind people have been (17) in those tests, making lots of (18) suggestions to the engineers who helped to produce Cyclops.

"This is the first time that blind people have ever done individual studies (19) a product was put on the market," Hingson said. "Most manufacturers believed that having the blind help the blind was like telling disabled people to teach other disabled people. In that (20) , the manufacturers have been the blind ones.

20()

A.occasion

B.moment

C.sense

D.event