OG 133

由 **Grace** » 2004-11-17 16:17

133. If X and Y are sets of integers, X*Y denotes the set of integers that belong to set X or set Y, but not both. If X consists of 10 integers, Y consists of 18 integers, and 6 of the integers are in both X and Y, then
X*Y consists of how many integers?

A. 6
B. 16
C. 22
D.30
E.174

Ans. B
這一題我不懂 10+18-6=22 為什麼22還要再扣掉6???
這一題的文字似乎有些tricky. Help~ ;)

由 **Behemoth** » 2004-11-17 16:52

Grace妹這題就是考集合概念的

白話的說題目問你 x聯集y有多少個數那你就x+y-(x交集y) 就是答案囉

這邊x=10 y=18 x交集y=6

由 **micht** » 2004-11-17 17:16

grace這題貼的好
我也犯這樣的錯

X*Y = the set of integers that belong to set X or set Y

所以求得Union 後要扣除 interaction 才會是 from set X OR Y

沒看清楚OR真的會選22 ^o)

可惡的ETS

由 **Grace** » 2004-11-18 10:29

謝謝 B桑耐心解惑...
ETS連考個數學都這樣高干真是厲害..

OG 133

OG 133

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