pp-T1-DS37

[Huang Hsin-Yi]

37
When 1,000 children were inoculated with a certain vaccine, some developed inflammation at the site of the inoculation and some developed fever. How many of the children developed inflammation but not fever?

(1) 880 children developed neither inflammation nor fever.

(2) 20 children developed fever.

ANS:C

難道develop inflammation人不能develop fever不然怎會是C勒?

[amazingslim]

設只有inflammation的人為:A
只有fever的人為:B
兩種都有的人:C
兩種都沒有的人:D
A+B+C+D=1000

(1)D=880
(2)B+C=20

(1)+(2)=>即可求出只有A=100

[Huang Hsin-Yi]

多謝大俠相助

[puja]

設只有inflammation的人為:A
只有fever的人為:B
兩種都有的人:C
兩種都沒有的人:D
A+B+C+D=1000

(1)D=880
(2)B+C=20

(1)+(2)=>即可求出只有A=100

這類的題目你把集合的概念再去抓來複習一遍就會更清楚了~~

N(A U B)=N(A) + N(B)- N( A 交集 B)

[canadacom_orig]

some developed inflammation at the site of the inoculation and some developed fever. How many of the children developed inflammation but not fever?

他的文章是用SOME

我如何可得知除了這兩種反應之外沒有第三種??

我想選E

這樣算題目不周嚴嗎??