[計量] 幾題數學請教

看板GRE作者 (Xavi)時間13年前 (2010/10/20 00:51), 編輯推噓5(5010)
留言15則, 8人參與, 5年前最新討論串1/4 (看更多)
1.if x and y are integers and xy+1 is even, which of the following must be odd? (A)(x^2)(y^2) (b)y(x+1) (c)x(x+y) (d)(x+y)^2 (e)(x+1)(y+1) 答案給的是A 但我覺得是D 想確定一下答案有沒有問題 2. when n articles are sold for p dollars each, the revenue obtained from the sales is $1 more than it would be if the price per article were $1 higher and one less article were sold. which of the following gives n in terms of p? (a)n=(p-1)/(p+1) (b)n=p+2 (c)n=p+1 (d)n=p (e)n=p-1 這題是我看不懂題目在問什麼 想請教一下板上的大家 謝謝 -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 112.78.76.219

10/20 00:52, , 1F
第一題A沒錯 隨便帶個3就知道了
10/20 00:52, 1F

10/20 00:53, , 2F
抱歉...是要奇數 這樣A不對
10/20 00:53, 2F

10/20 00:53, , 3F
....我又眼殘了 A沒錯
10/20 00:53, 3F

10/20 00:54, , 4F
一樣帶個數字進去看看
10/20 00:54, 4F

10/20 00:58, , 5F
第一題A是對的 E奇數加奇數有可能是偶數
10/20 00:58, 5F

10/20 00:59, , 6F
打錯 D選項
10/20 00:59, 6F

10/20 01:11, , 7F
二是B吧 n個東西 ㄧ個賣p元 當價錢提高1元 數量少1時
10/20 01:11, 7F

10/20 01:11, , 8F
總價可以多賺1元
10/20 01:11, 8F

10/20 01:12, , 9F
(n-1)(p+1)=np+1 應該是搂~
10/20 01:12, 9F

10/20 01:18, , 10F
抱歉剛忘了說 我好像打錯符號了平方我打成^
10/20 01:18, 10F

10/20 01:20, , 11F
然後第二題答案是給D
10/20 01:20, 11F

10/20 11:27, , 12F
答案是d沒錯 b大翻錯了!
10/20 11:27, 12F

10/20 12:21, , 13F
bul大式子應該是np-1=(n-1)(p+1)
10/20 12:21, 13F

12/02 19:21, , 14F
答案是d沒錯 b大翻錯 https://muxiv.com
12/02 19:21, 14F

04/13 23:51, 5年前 , 15F
總價可以多賺1元 http://yaxiv.com
04/13 23:51, 15F
文章代碼(AID): #1ClSo2KJ (GRE)
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文章代碼(AID): #1ClSo2KJ (GRE)