抛掷两枚骰子,设出现的点数之和是6,7,8的概率依次是P(A),P(B),P(C),则(  )A.P(A)=P(

2024-11-09 10:38:19
推荐回答(1个)
回答1:

先后抛掷两枚骰子,出现的点数共有:
(1,1),(1,2),(1,3),(1,4),(1,5),(1,6),
(2,1),(2,2),(2,3),(2,4),(2,5),(2,6),
(3,1),(3,2),(3,3),(3,4),(3,5),(3,6),
(4,1),(4,2),(4,3),(4,4),(4,5),(4,6),
(5,1),(5,2),(5,3),(5,4),(5,5),(5,6),
(6,1),(6,2),(6,3),(6,4),(6,5),(6,6),共36种
其中点数之和是6的有5种,故P(A)=

5
36

点数之和是7的有6种,P(B)=
6
36

点数之和是8的有5种,故P(C)=
5
36

∴P(A)=P(C)<P(B).
故选A.