弱问一个数学描述和一道DS题

teddyabc

从数学上说， at least 应该不等于 greater than吧？

为何下面这个题选C呢， 我怎么看怎么觉得选E。。。 求指点
During July, a mail order retailer received 3300 order for amounts less than $100, and 1100 orders for amounts of at least $100. what was the average size of an order in July?
(1) The gross sales from the orders less than $100 equaled the gross sales from the orders greater than $100
(2) The orders for less than $100 account for a total of $134000 in gross sales

haileywang

$X : total $ for orders <$100
$Y: total $ for orders =$100
$Z: total $ for orders >$100

Stimulus give the # of orders for $X and the # of orders for ($Y + $Z)

1) X = Z
2) X= 134,000

So combining 1) and 2), you get X=Z= 134,000.  But we still do not know Y.

LZ is right.  Choose E.

avalon9527

average size of an order = total gross sales / 4400 orders
1) the gross sales of amount <100 = the gross sales of amount >=100
2) the gross sales of amount <100 = 134000
so, if both 1) and 2) are true, then the average size should be 134000*2/4400

avalon9527

it seems i made a mistake.

bigpig

回复 3# avalon9527


    哪里错了？

bigpig

回复 2# haileywang


    我同意您的观点

teddyabc

THX， 所以说题目混淆了at least和greater than。

确认一下踏实多了。22号考试，参观别人家的小狗狗中，顺便祝所有2月G友好运