[数学讨论稿3] 已阅而是就输血讨论稿201-300（更新至300，2.16 -22:15)

jingqh

The answer to Q221 should be C, right??
Given the proportional relationship in (2), we still do not know the value of either a or b. We have to combine (1) and (2).

jingqh

Q240: we can infer that y=5 from (1). So should be A, not C.

jingqh

Q241 no clue at all......

hana0614

Q262 选E啊，把式子列出来就一目了然了

jingqh

Q262 选E啊，把式子列出来就一目了然了

-- by 会员 hana0614 (2012/2/14 10:30:07)

Why? Can you explain more? I don't quite understand this problem. I thought it was A.

hana0614

选项看错了

eryababy

Q240: we can infer that y=5 from (1). So should be A, not C.

-- by 会员 jingqh (2012/2/14 6:08:15)

但是如果x不是integer的话还是也能推到y=5么。。。

cuifang1

y=(2*5)^4  x=3 root of  1/2 if not B

哎呦喂呀

242.【alancui】5 machines with the same productivity, if 4 machines work together, it will take A hours to finish a job. If put 5 machines into work, how many hours will be saved. (A是个特定的值，具体记不得了，这道还是很简单的）
A乘以(4/5-1)=四分之一Ａ

不应是五分之一A么。。

eryababy

242.【alancui】5 machines with the same productivity, if 4 machines work together, it will take A hours to finish a job. If put 5 machines into work, how many hours will be saved. (A是个特定的值，具体记不得了，这道还是很简单的）
A乘以(4/5-1)=四分之一Ａ

不应是五分之一A么。。

-- by 会员 哎呦喂呀 (2012/2/15 19:12:46)

恩恩，对的呢