Question

Quine

請問這題是怎麼算出機率是1/6的呢

BA
14. John and Mary are planning to start a family. John was married once before, and he and his first wife had a child with cystic
fibrosis. The brother of his current wife, Mary, died of cystic fibrosis. What is the probability that John and Mary will have a
baby with cystic fibrosis? (Neither John, Mary, nor their parents have cystic fibrosis.)
A a
A) 1/4 B) 1/6 C) 1/8 D) 1/12
E) 1/16 Mary : AA or Aa (4)
John Aa
211
A
a
(aa
Lit
2 x 4 =
hich
1186

Answer 1

✨ 最佳解答 ✨

FuTony

Mary是Aa的機率應該要是2/3，因為Mary不可能是aa 。因此(2/3)*(1/4)=1/6

FuTony

看圖

Answer 2

star詠嘆星空

Mary要分成兩個狀況

Quine

感謝解答～