作者duwaptt (uu)
看板GRE_Verbal
標題請問數學題目
時間Fri Sep 14 17:52:44 2007
In a graduating class of 236 students, 142 took algebra and 121 took chemistry.
What is the greatest number of students that could have taken both algebra and
chemistry?
A:21 B:27 C:37 D:121 E:142
答案是D 我想好久都想不出來 麻煩高手指導 謝謝
我是想 142 +121=263 263-236= 27 但是不對 哀
2. If 55 percent of a group of people have brown hair and 80 percent of the
same group do not have red hair, what fraction of those who do not have brown
hair have red hair? 答案是5/9
真的想不出來!
3 一個數學觀念: 一個圓 以直徑當成內接三角形的底 以圓上任一點畫個三角形
會因為底邊都一樣長 而造成頂角(圓上的角)度數一樣嗎??
4 N= (K+R/S)/(t/v) In the equation above K, R, S, t and v represent positive
numbers. Multiplying which one of these numbers by 2 will reduce the value of
N to 1/2 of its present value?
答案是t 不過將S變兩倍 好像也可以使N變1/2 ??
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◆ From: 59.104.172.241
1F：推 gts:1.他沒有說代數課跟化學課是同一時間阿!所以上 59.117.163.104 09/14 18:11
2F：→ gts:化學課的人可以上代數課!取比較小那一個! 59.117.163.104 09/14 18:12
3F：推 gts:3.圓周角的角度 = 所對弧的角度的1/2, 59.117.163.104 09/14 18:19
4F：→ gts:所以一圓直徑為斜邊內接三角形為直角三角形 59.117.163.104 09/14 18:19
5F：推 eadanlin:第二題我怎麼算4/9 QQ 140.113.92.6 09/14 18:48
6F：推 eadanlin:第四題S*2且K/2才能使N減半 140.113.92.6 09/14 18:51
7F：推 kgc:2.55%的人是棕髮, 80%的人不是紅髮, 問不是棕븠 58.99.17.52 09/14 19:00
8F：→ kgc:髮的人中 是紅髮的機率? 58.99.17.52 09/14 19:00
9F：→ kgc:這是條件機率 應該4/9 58.99.17.52 09/14 19:00
10F：推 niwhu:第二題是問fraction喔...不是機率 140.109.66.205 09/14 19:36
11F：推 niwhu:非紅髮的包含了棕髮的集合，換言之非棕髮的ꐠ 140.109.66.205 09/14 19:40
12F：→ niwhu:包含紅髮的集合 140.109.66.205 09/14 19:42
13F：推 niwhu:fraction是機率啦(sorry上面當我沒講) 140.109.66.205 09/14 19:45
14F：推 duwaptt:sorry 第2題是4/9才對 59.104.172.241 09/14 19:57
15F：→ duwaptt:不過 第二題 能否提供算式 我不會列式 59.104.172.241 09/14 19:58
16F：推 niwhu:0.2/0.45 140.109.66.205 09/14 20:11
17F：推 duwaptt:謝謝 59.104.172.241 09/14 20:14