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saphirelucky

同意shaoshao7的猜测

kittymiaomiao

以下是引用岁寒三宝在2005-10-8 14:34:00的发言：

看似很简单的题目，我就是做不对，哭死了。大家帮帮忙，谢谢

第一题

On a certain day, Tim invest $1,000 at 10 percent annual interest, compound annually, and Lana invested $ 2,000 at 5 percent annual interest, compound annually. The total amount of interest earned by Tim’s investment in the first 2 years was how much greater than the total amount of interest earned by Lana’s investment in the first 2 years?

5,15,50,100,105

答案是A

可是我算着：

1000(1+10%)^2=1210

2000(1+5%)^2=2200

210-220=10，选项中也没有：（

呵呵，你粗心了，2000(1+5%)^2=2205

第二题

If xy=1, what is the value of 2(X+Y)^2比上2(X-Y))^2?

答案是16，我不会做：（：（

这道题我也错了,考试的时候就没算出来，我也正郁闷呢！！楼主的题目没写错，请nn指导一下

第三题

If m,r,x and y are positive, is the ratio of the m to r equal to the ratio of x to y?

1)      the ratio of m to y is equal to the ratio of x to r

2)      the ratio of m+x to r+y is equal to the ratio of x to y

答案是B

可是B是怎么推出来的呢？我选E

(m+x)/(r+y)=x/y ---> my+xy=xr+xy --->my=xr ---> m/r=x/y

lemony55

以下是引用ayang1017在2005-10-8 19:50:00的发言：

仔细看题，mm

第一题：

[1000×（1＋10％）^2-1000*(1+10%)]-[2000*(1+5%)^2-2000*(1+5%)]=110-105=5

我觉得没必要减第一年的本息啊，题目说in the first 2 years，我翻译为“在第一个两年”，就是说是整体的。如果减就是说是只要第二年的利息就行了

pheobe

同意楼上

gps4145

我想第一题应该是这样解：

[1000×（1＋10％）^2-1000]-[2000*(1+5%)^2-2000]=210-205=5