PREP+FF数学，裸奔在即，盼望NN救命！

daisy1980626

3纠正一下，是A,粗心了。。。

GMATdeJULY

2的答案是E,9楼正解

GMATdeJULY

第三题如果是A的话，加法也可以，应该是C

GMATdeJULY

8.DS题。在XY平面上，问直线L的Y截距。

1.L的斜率是Y截距的3倍

2.X轴上的截距是-1/3

答案是E。我选的C。俩个条件直接可以确定L的一次函数表达式啊。。为什么是E呢？？。

kykosd

建议把答案先放上去

kykosd

第7题说的是of the 73 scores

意思是上面一共有73个成绩，问中间的那个在哪个区域

2+10+16+27+18=73

kykosd

截距的那道

（1）给出 y=3bx+b,,,,改写就变为 x=(1/3b)y-1/3   就已经知道了x轴上的截距是-1/3，

 (2) 明显单独不能成立，  给的还是（1）中已经知道的x的截距所以没有用

   

GMATdeJULY

哦这题懂了。谢谢KYKOSD NN！

我答案写在题目下面呢！

GMATdeJULY

最后两道！

10. When a certain tree was first planted, it was 4 feet tall, and the height of the tree increased by a cinstant amount each year for the next 6 years. At the end of the 6th year, the tree was 1/5 taller than it was at the end of the 4th year.By how many feet did the height of the tree increase each year？

A. 3/10,B 2/5,C1/2,D.2/3,E6/5答案选D

我的思路是设每年恒定的增长数为F，那第6年是4+5F，第4年是4+3F。问题是“the tree was 1/5 taller than it was at the end of the 4th year”这句话怎么理解？

是（4+3F）×（1+1/5)=4+5F呢，还是 4/5×（４＋５Ｆ）＝４＋３Ｆ？还是4+3F+1/5=4+5F？

无论是哪个式子算出来都没有题目给的选项。。迷茫。。

11. DS题。During a one day sale, a store sold each sweater of a certain type for $30 more than the store's cost to purchase each sweater. How many of these sweaters were sold during the sale?

1.During the sale, the total revenue from the sale of these sweaters was $270

2.During the sale, the store sold each of these sweaters at a price that was 50 percent greater than the store's cost to purchase each sweater

答案是C，我选的A。REVENUE不就是卖价-买价=30？总REVENUE是270，卖的个数就是9个啊。。。错哪儿了，望NN指正。

lemonrr

第10题的，它是说第6年的比第4年的高1/5，即比例的分母应该是第4年的

               （4+6x）/（4+4x）=6/5    6x=4    x=2/3

11题，revenue= purchase price*n   也就是售价* 卖的数目，  a显然算不出的