Two math

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1. In a retail store, the average (arithmetic mean ) sale for month M was d dollars. Was the average (arithmetic mean)sale for month J at least 20 percent higher than that for month M?
1) For month M, total revenue from sales was $3500
2) For month J, total revenue from sales was $6000;

I choose C, but the key is E.
question: a)what does average sale for month M mean?
b) any difference between sale and revenue?

2. Running at the same constant rate, 6 identical machines can produce a total of 270 bottles per minute. At this rate, how many bottles could 10 such machines produce in 4 minutes?
a)648 b)1800 c)2700 d)10800 e)64800
I choose B while the key is D.

any one can explain? //bow!

seanql

I have the same questions, who would like to give your hands?

browse

up 一下，高人帮帮

model

我的答案也是C，B，答案没错吧？

Liza0118

me too

zjw007

第一题是不是由于没告诉多少天,因为问的是average, not total revenue. but if let me choose, i will take "c" too.

browse

这两体都是xdf教材上的。
section 9 No.2 & 补充No.104
又踢得可以看一下

peggymm

我看了原题，做的时候也是被faint to death，尤其是section9竟然上来第二个题就错……我想我们做的是对的，是答案错了吧；这种情况不罕见，xdf阅读上补充材料的答案就有错的。

browse

以下是引用peggymm在2003-12-19 22:03:00的发言：
我看了原题，做的时候也是被faint to death，尤其是section9竟然上来第二个题就错……我想我们做的是对的，是答案错了吧；这种情况不罕见，xdf阅读上补充材料的答案就有错的。

谢谢peggymm.
别忘了给我送冬冬。