[原创] 截止10.3号 11道数学JJ题....一定要看

jinghezhao

 

13、If m and n are positive integers, is m/n a terminal decimal?

1). 90<m<100

2). n=4

答案是什么啊 B 还是 C 啊

我的答案是B，因为任何正整数在其商可保留小数的前提下都可被4除尽。请讨论！

cornhusker

关于coin:

penny: 1cent

nickle:5cents

dime: 10cents

quarter:25cents

美国常用这四种，50cents&100cents没有特别的叫法，若出到50cents 和100cents的题，一定会说明金额的。

后面来讨论题。

cornhusker

0. If x is a prime number, is 3xy an even number?
    
(1) x>2
     
(2) y is odd

my answer:C

1. Is X>Y?

1). (X-Y)/X>0

2). (X^2-Y^2)/X^2>0

my answer:E

2. As the figure above shows, AB=BC=8, CD=2, angle B and angle C are right angle, and

AE=ED=13. What is the area of the ABCDE?

my answer:100

3. A plane traveled k miles in the first 96 minutes of flight time. If it completed the remaining 300 miles of the trip in t minutes, what was its average speed, in mils per hour, for the entire trip?

my answer:60*(300+K)/(96+t)

4. Is the positive integer x an even nuber?

1). If x is divided by 3, the remainder is 2

2). If x is divided by 5, the remainder is 3

my answer:E

5. What is the tens digit of positive integer x?

1). X divided by 100 has a remainder of 30

2). X divided by 110 has a remainder of 30

my answer:A

6. In the xy-plane, are the points (r,s) and (u,v) equidistance from the origin?

1). r+s=1

2). u=1-r and v=1-s

my answer:C

7. Working independently, Tina can do a certain job in 12 hours. Working independently, Ann can do the same job in 9 hours. If Tina works independently at the job for 8 hours and then Ann works independently, how many hours will it take Ann to complete the remainder of the job?

my answer:3

8. If m and n are positive integers, is m/n a terminal decimal?

1). 90<m<100

2). n=4

my answer:B

9. Mary has 11 more nickels than quarters. How many coins does she have if the total value of her coins is $2.65?

my answer:25

10. A and B are in a line to purchase tickets. How many people are in the line?

1). There are 15 people behind A and 15 people in front of B

2). There are 5 people between A and B

my answer:E

[此贴子已经被作者于2006-10-5 0:54:43编辑过]

111cara

感谢以上做贡献滴众位同胞~~~

ailff

 If x is a prime number, is 3xy an even number?
    
(1) x>2
     
(2) y is odd

怎么是c? BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.？？

我觉得是E。Statements (1) and (2) TOGETHER are NOT sufficient

cpcjustin

No 8# 's answer is B.

quarter=25 penny

whythisway

以下是引用ailff在2006-10-5 3:10:00的发言：

 If x is a prime number, is 3xy an even number?
    
(1) x>2
     
(2) y is odd

怎么是c? BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.？？

我觉得是E。Statements (1) and (2) TOGETHER are NOT sufficient

odd x odd=odd

3 is odd; x > 2 and x is a prime, so x is odd

3x is odd, so if multipled by y (also odd), the answer is odd.

tonyli

11题选c吧，因为给出的条件下只可能b在前，a在后。如果反之，就和第二个条件冲突。

ailff

谢谢你的解释，我其实是懂得，只是迂了一点

fiddle50

第9題

nickel 為五美分 ，quarter為四分之一美元

n=q+11

0.5(q+11)+0.25q=2.65

解得q=7,n=18,total 25 coins