ใจ็ฝ็1ๅใๅใๅบใๅ ดๅ
Aใใ่ตค็ใ2ๅๅใๅบใ็ขบ็ใฏ
2C2 1
5C2
=
10
Bใใ่ตค็1ๅใจ็ฝ็1ๅใๅใๅบใ็ขบ็ใฏ
3C1 ร 4C1
4
7C2
7
ใใใใฃใฆ,ใใฎใจใใฎ็ขบ็ใฏ
20
(2)1ไบบ็ฎใจๅใ็ฎฑใ้ธใใ ใจใใซ,ๅฝใใใใ
ๅผใ็ขบ็ใฏ
1ไบบ็ฎใจ็ฐใชใ็ฎฑใ้ธใใ ใจใใซ,ๅฝใใใใ
ใใใ
ใๅผใ็ขบ็ใฏ
3
PE(A)ร
PE(A)
10
5
3
- 1/2 ร 1/2+1/+ ร 10/15
10
3
510
=
0.375
8
ใใใใฃใฆ, 1ไบบ็ฎใจ็ฐใชใ็ฎฑใใใใใๅผใ
ๅ ดๅใฎใปใใ,ๅฝใใใใใๅผใ็ขบ็ใฏๅคงใใใ
82ๅใฎใใใใใๆใ
PE(A)ร
ร
||
58 1386
4
(+PE(A)
29
29
38
0.36111๏ฝฅ๏ฝฅ๏ฝฅ
13/16
่ฉณ็ดฐ่งฃ็ญ 233
52= 25 (ๅ)
(ii) ็พใฎไฝใซ3ใใใๅ ดๅ
ๅใฎไฝใซ3ใพใใฏ4ใใใๅ ดๅใฏ,ไธใฎไฝใฏ,
5ใคใฎๆฐๅญใฎไฝใใใฆใใใใใ
2ร5=10 (ๅ)
ๅใฎไฝใ2ใฎๅ ดๅใฏ,ไธใฎไฝใฏ1ไปฅไธใฎๆฐใใ
ใใฐใใใใ 4ๅ
ใใใใฃใฆ 10 + 4 = 14 (ๅ)
(i), (ii)ใใ, ๅ
จ้จใง 25+14= 39 (ๅ)