陆俊爸  发表于 2011-4-27 13:42:40| 2979 次查看 | 0 条回复
本帖最后由 陆俊爸 于 2011-4-27 13:46 编辑

  第一期英文奥数推出之后,家长和同学们都反映非常好,说受益匪浅。因此我们推出系列二。但同时也有些问题,很多家长反映孩子觉得比较难。首先希望家长多多辅导孩子,其实奥数知识同学们是都会的,但是有些英文单词不认识,希望家长帮助孩子共同提高。另外,我们只是希望那些比较优秀的同学和学有余力的同学来做,没有必要所有同学都要会做。

  1、Did you know? In the decimal number system (base 10) ten different digits, 0 to 9, are used to write all the numbers. In the binary number system (base 2) two different digits are used, i.e. 0 and 1.

  Which one of the following numbers is not a valid number in the
octal number system (base 8)?
A) 128 B) 127 C) 126 D) 125 E) 124

  2、The number of diagonals that can be drawn in a regular polygon with
twenty sides (cosign) is_____.

  3、If a and b are integers, 22.jpg

is equal to_____.

  4、Two numbers are in the ratio 2 : 3. When 4 is added to each number the ratio changes to 5 : 7.The sum of the two original numbers is____.

  5、The greatest number of Mondays which can occur in 45 consecutive
days is____

  6、Saul plays a video game in which he scores 4 for a hit and lost 6 for a miss. After 20 rounds his score is 30. The number of times he has missed is____.

  7、Three girls A, B and C run in a 100 m race. When A finishes, B is 10 m
behind A and when B finishes C is 20 m behind B. How far in metres was C from A when A finished?(Let’s assume all the athletes run at a constant speed)

  8、The areas of the faces of a rectangulabox are 84 cm2 , 70 cm2and 30 cm2.The volume of the box in cm3  is____.

  9、You have 3 weights: 1 kg, 3 kg and 9 kg as well as an equal arm balance, as shown. How many different weight objects can you weigh with these three?
[Remember the weights may be placed on either side]

  参考答案:

  1、A 考察我们学过的简单的进制问题,显然8进制中没有8出现
  2、170 找规律,公式为n×(n-3)÷2
  3、1 定义新运算,就是求379÷6的余数。

  4、40,16和24
  5、
7
  6、
5
  7、28米,根据距离比求出速度比,三者的速度比为1:9/10:
18/25
  8、420 分解质因数

  9、13种