問題---資料充分性

[玩命去]

想請問大家在做資料充分性的題目都是怎樣著手的....我每次遇到那種很抽象的問法就不知道開怎麼辦...我覺得應該要列出式子.....可是又不太會列....各位高手能不能幫幫我阿....提供一下你們的技巧好嗎?.....謝謝你們了


魚老大對不起喔....我列出幾個題目....這幾個類型的題目我真的不太在行
What is the value of (x - y)4?
(1) The product of x and y is 7.
(2) x and y are integers.

If 2 different representatives are to be selected at random from a group of 10 employees and if p is the probability that both representatives selected will be women, is p > ?
(1) More than of the 10 employees are women.
(2) The probability that both representatives selected will be men is less than .
What is the probability that a student randomly selected from a class of 60 students will be a male who has brown hair?
(1) One-half of the students have brown hair.
(2) One-third of the students are males.
諸如此類的題目.....我應該怎麼想比較周全呢?.....謝謝大家囉!!

[魚]

喬巴 !

我很想回答你的問題 !


不過 實在是太抽象了你

要不要舉個實際的例子來

[汪汪北鼻]

What is the value of (x - y)4?
(1) The product of x and y is 7.
(2) x and y are integers.

第一步，列出式子
1)xy=7, 求(x-y)^4
--->x,y 有太多可能性了for example, x=1/2, y=14, x=7,y=1 諸如此類都會造成(x-y)^4 有不同的結果，所以不充分

注意，通常A錯時，答案就剩BCE選了，答對率提高至33%

2) x,y為整數 也不知道為多少，答案有太多可能性了

注意，B又錯時，答案剩CE決選，二個選一個，正確率50%, 選錯也是命了

第二步，同時考慮1)2)
xy=7, x,y為整數，則 X=1,7,-1,-7 y=7,1,-7,-1
代回題目所給之條件(x-y)^2得唯一解 36

所以答案為C