✔ 最佳答案
一盒子有三張卡 , 分別記有數字2,3,4 ; 一袋子有二個球,分別記有6,7. 若從盒子及袋子分別隨意抽出一張卡及一個球 , 求所抽出的數字之和為10的概率
Summary: 3 Card in box no.2,3,4,
2 ball in bag no. 6,7
ball 6 should be match with card 4
ball 7 should be match with card 3
total 概率 = 1/3 X 1/2 = 1/6 for each combitation. Therefore 所抽出的數字之和為10的概率 = 2X1/6 =2/6=1/3
or
1/2 (any ball 6 or 7) X 1/3(match card) + 1/2 (any ball beside of perious one) X 1/3(match card)
=1/2X1/3 +1/2X1/3
=1/6+1/6
=2/6
=1/3