问题 解答题

初三(8)班尚剩班费m(m为小于400的整数)元,拟为每位同学买1本相册.某批发兼零售文具店规定:购相册50本起可按批发价出售,少于50本则按零售价出售,批发价比零售价每本便宜2元,班长若为每位同学买1本,刚好用完m元;但若多买12本给任课教师,可按批发价结算,也恰好只要m元.问该班有多少名同学?每本相册的零售价是多少元?

答案

设该班有x名同学,每本相册的零售价是y元,

则xy=(x+12)(y-2)①,且整数x满足38≤x<50②,

由①得12y-2x-24=0,y=

x
6
+2,xy=
x2
6
+2x③,

由③及xy=m为整数,知整数x必为6的倍数,再由②得x只可能为42或48,

此时相应的y为9或10,

但m<400,所以x=42,y=9.

故答案为:该班有42名同学,每本相册的零售价是9元.

单项选择题

D

Besides entertainment and beautiful lanterns, another important part of the Lantern Festival, or Yuanxiao Festival is eating small dumpling balls made of glutinous rice flour. We call these balls Yuanxiao or Tangyuan. Obviously, they get the name from the festival itself. It is said that the custom of eating Yuanxiao originated during the Eastern Jin Dynasty in the fourth century, then became popular during the Tang and Song periods.

The fillings inside the dumplings or Yuanxiao are either sweet or salty. Sweet fillings are made of sugar, walnuts, sesame (芝麻), osmanthus flowers (桂花), rose petals, sweetened tangerine (橘子) peel, bean paste, or jujube paste(枣子酱). A single ingredient or any combination can be used as the filling. The salty variety is filled with minced meat(肉末儿), vegetables or a mixture.

The way to make Yuanxiao also varies between northern and southern China. The usual method followed in southern provinces is to shape the dough of rice flour into balls, make a hole, insert the filling, then close the hole and smooth out the dumpling by rolling it between your hands. In North China, sweet or nutmeat stuffing is the usual ingredient. The fillings are pressed into hardened cores, dipped lightly in water and rolled in a fiat basket containing dry glutinous rice flour. A layer of the flour sticks to the filling, which is then again dipped in water and rolled a second time in the rice flour. And so it goes, like roiling a snowball, until the dumpling is the desired size.

The custom of eating Yuanxiao dumplings remains. This tradition encourages both old and new stores to promote their Yuanxiao products. They all try their best to improve the taste and quality of the dumplings to attract more customers.

Which country does the Lantern Festival come from().

A. China.

B. South Korea.

C. Jin Dynasty.

D. Tang and Song periods.

问答题