数学低能儿，非难题求解！

wfuwa

实在是查不到曾经有人提出这些问题 只能敲出来，求大家给指个明路：

42套数学第一套的第5题：

At a certain diner, a hamburger and coleslaw cost $3.59 , and a hamburger and french fries cost $4.40. If french fries cost twice as much as coleslaw, how much do french fries cost?

A.$0.30  B.$0.45  C.$0.60  D.$0.75  E.$0.90

我列的式子：h+c=3.59    h+f=4.40   f=2c       最后得出f=1.8 没有这个答案啊，还是我的思路彻底错了？

第8题：

A certain culture of bacteria quadruples every hour. If a container with these bacteria was half full at 10:00 a.m., at what time was it one-eighth full?

A.9:00a.m.   B7:00a.m.   C.6:00a.m.    D.4:00 a.m.     E.2:00 a.m.

1/8满的时候是几点，1/2满的时候是10点，从1/8到1/2 不应该1/2减去1/8吗？剩下3/8 增出这3/8用多少时间？是这样吗？彻底晕了~~~

不好意思我怕我敲的这些丢了，先发表，不会的还有。在二楼写上。

wfuwa

第9题：

A1,Lew,and Karen pooled their funds to buy a gift for a friend.A1 contributed $2 less than 1/3 of the cost of the gift and Lew contributed $2 more than 1/4 of the cost .If Karen contributed the remaining $15, what was the cost of the gift?

A.$24  B.$33  C.$36 D.$43 E.$45

wfuwa

第12题：

In 1979 approximately 1/3 of the 37.3 million airline passengers traveling to or from the United States used Kennedy Airport. If the number of such passengers that used Miami Airport was 1/2 the number that used Kennedy Airport and 4 times the number that used Logan Airport, approximately how many millions of these passengers used Logan Airport that year?

A.18.6  B.9.3  C.6.2  D.3.1  E.1.6

[此贴子已经被作者于2009-1-31 2:12:24编辑过]

wfuwa

第13题：

A certain basketball team that has plyed 2/3 of its games has a record of 17 wins and 3 losses. What is the greatest number of the remaining games that the team can lose and still win at least 3/4 of all of its games?

A.7  B.6  C.5  D.4  E.3

fatpeng

In your reasoning,

h+c=3.59

h+f=4.4

---> f-c=0.81-->c=0.81-->f=1.62

still no answer in the list

fatpeng

quadruples

的意思是乘以四倍的增长

10点的时候一半满，9点的时候，就是1/8满

fatpeng

9.

假设礼物价格x

A 出了x/3-2

L 出了2+x/4

K 出了 15

列方程x/3-2+2+x/4+15=x

x=36

fatpeng

12

Kennedy k=37.3/3

Miami m=k/2

Logan L=m/4

m~~1.6M

fatpeng

已经打了17+3=20场

一共有20/（2/3）=30场要打

需要赢至少30*3/4=22.5，也就是23场

已经赢了17场，还要赢6场

剩下10场里面，最多输10-6=4场

wfuwa

太感谢fatpeng了！我好好看一下！