- UID
- 1119793
- 在线时间
- 小时
- 注册时间
- 2015-6-6
- 最后登录
- 1970-1-1
- 主题
- 帖子
- 性别
- 保密
|
-
In a certain game, a large container is filled with red, yellow, green, and blue beads worth, respectively, 7, 5, 3, and 2 points each. A number of beads are then removed from the container. If the product of the point values of the removed beads is 147,000, how many red beads were removed?
(A) 5
(B) 4
(C) 3
(D) 2
(E) 0
答案是D
以下是解释:
Arithmetic Properties of numbers
From this, the red beads represent factors of 7 in the total point value of 147,000. Since 147,000 = 147*(1,000), and 1000= 10^3, then 147 is all that needs to be factored to determine the factors of 7. Factoring 147 yields 147= 3*49= 3*(7^2). This means there are 2 factors of 7, or 2 red beads.
看了OG的解析之后更迷糊了,希望大神帮忙指点一下好么?
|
|