dua buah dadu dilemparkan bersama sama satu kali. peluang muncul jumlah mata dadu genap yang kurang dari 8 atau jumlah mata dadu ganjil yang kurang dari 11 adal

Mapel : Matematika
Kelas : IX SMP
Bab : Peluang

Pembahasan :
n(s) = 6² = 36
n(A) = {(2,2)(2,4)(4,2)] = 3
n(B) = {(1,1)(1,3)(1,5)(3,1)(3,3)(3,5)(5,1)(5,3)(5,5)(6,1)(6,3)} = 11

P = n(A)/n(s) + n(B)/n(s)
P = 3/36 + 11/36
P = 14/36
P = 7/18

Dua dadu dilempar = n(S) = 6 . 6 = 36

Muncul jumlah dadu genap kurang dari 8
2 = (1, 1) = 1
4 = (2, 2), (1, 3), (3, 1) = 3
6 = (1, 5), (5, 1), (2, 4), (4, 2), (3, 3) = 5
n(A) = 1 + 3 + 5 = 9

Muncul jumlah mata dadu ganjil kurang dari 11
3 = (1, 2), (2, 1) = 2
5 = (1, 4), (4, 1), (2, 3), (3, 2) = 4
7 = (1, 6), (6, 1), (2, 5), (5, 2), (3, 4), (4, 3) = 6
9 = (3, 6), (6, 3), (4, 5), (5, 4) = 4
n(B) = 2 + 4 + 6 + 4 = 16

Peluang = P(A U B)
= P(A) + P(B)
= 9/36 + 16/36
= 25/36