GWD-17-Q18.Q33.Q34共三題, 謝謝!!

[訪客]

拜託大家了.....謝謝!感激!!

GWD-17-Q18
Last year the price per share of Stock X increased by k percent and the earnings per share of Stock X increased by m percent, where k is greater than m. By what percent did the ration of price per share to earnings per share increase, in terms of k and m?
A. k/m %
B. (k-m)%
C.〔100(k-m)〕/(100+k)%
D.〔100(k-m)〕/(100+m)%
E.〔100(k-m)〕/(100+k+m)%

GWD-17-Q33
A photographer will arrange 6 people of 6 different heights for photograph by placing them in two rows of three so that each person in the first row is tanding in front of someone in the second row. The heights of the people within each row must increase from left to right, and each person in the second row must be taller than the person standing in front of him or her. How many such arrangement of the 6 people are possible?
A. 5
B. 6
C. 9
D. 24
E. 36

GWD-17-Q34
If Line k in the xy-plane has equation y= mx+b, where m and b are constants, what is the slope of k?
(1) k is parallel to the line with equation y= (1-m)x+ b+ 1.
(2) K intersects the line with equation y= 2X +3 at the point (2,7)

線性的東西觀念比較弱,麻煩解釋的詳細一點,謝謝!!

[ipas3]

GWD-17-Q18
假設
price per share of Stock X = P
earnings per share of Stock X = E
按照題意
P=P*100%增加成P(100+k)%
E=E*100%增加成E(100+m)%
所以
the increasement (as in percentage) of the ration of price per share to earnings per share
= 100% * { [P(100+k)% / E(100+m)%] - (P*100%/E*100%) } / (P*100%/E*100%)
約分 P, E 與 % (但100%的%並沒有被約分掉,別刪太快) 再整理一下,
= 100%* {[(100+k )/(100+m)]-1}
= 100%* (k-m)/(100+m)
答案是(D) (對不起這邊我一開始打成C, 上面算式是對的, 感謝樓主解答, 為避免誤導後人, 已用編輯修正, 還請各位海函)

GWD-17-Q33
坦白說這題除了硬算我也不會解, 期待高人出手相助
但依題意位置為
ABC (front)
DEF
A必為最矮的, F必為最高的, 剩下4個位置任意排列4!=24, 可以先刪了(D)(E), (亂猜命中率從20%增加到33%...Orz...)
(這邊也補充一下, 意思是even剩下四個位置可以任排, 最多也只有4!=24, 所以D,E答案為非, 雖然說這樣刪去幫助不大就是...謝謝樓主回應)

GWD-17-Q34
直線y-mx+b斜率即為m,
(1)
y= (1-m)x+ b+1, 斜率為(1-m)
so 1-m=m, m=1/2
(2)
與定直線交於特定點的線有無限多條.
答應是(A)

請問有正解嗎?


( jw1103.hsu@gmail.com 徵有圖的PP1/PP2 math, thanks!)

[訪客]

Sorry...忘記留下正確答案!
GWD-17-Q18 (D)
GWD-17-Q33 (C)
GWD-17-Q34 (A)

Q33應該不是這樣,題目說每個人的身高不同,而且必須由矮至高(由左至右),所以沒有辦法中間四人去排列,位置會是固定的
我不知道我的理解是否正確,請高手幫幫忙...還是謝謝你的解答!!