作者zingy (zingy)
看板GMAT
标题Re: [计量] GWD6-25,28
时间Wed Dec 26 20:23:43 2007
※ 引述《NOWIZKI (== ==)》之铭言：
: Q25:
: If the number 52,1n9, where n represents the tens digit, is a multiple of 3,
: then the value of n could be which of the following?
: A. 6
: B. 5
: C. 3
: D. 1
: E. 0
: Answer: d
我猜是因为那个","让您迷惑了!!
有一个数 521n9 可以被3整除 则n可能是
5+2+1+n+9=17+n 可以被3整除 故n=1,4,7 所以是D
: Q28:
: Last Sunday a certain store sold copies of Newspaper A for $1.00 each and
: copies of Newspaper B for $1.25 each, and the store sold no other newspapers
: that day. If r percent of the store’s revenues from newspaper sales was from
: Newspaper A and if p percent of the newspapers that the store sold were
: copies of newspaper A, which of the following expresses r in terms of p?
: A. 100p / (125 – p)
: B. 150p / (250 – p)
: C. 300p / (375 – p)
: D. 400p / (500 – p)
: E. 500p / (625 – p)
: Answer: d
: 请问一下这两题要怎麽去解 去大陆的网站看就只有一个不懂而已
设共卖出 X 份
A 的收益= X*p%*1
B 的收益= X*(1-p%)*1.25
X*p% A报的收益
_______________________ _______________
r= X*(1-p%)*1.25 + X*p%*1 = A报+B报 的收益
=400p/(500-p)
^^ 我凑不到这100怎麽来的...T_T
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※ 编辑: zingy 来自: 61.217.218.247 (12/26 20:41)