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12的有1种,故P 1 =
点数之和是11的有2种,故P 2 =
点数之和是10的有3种,故P 3 =
故P 1 <P 2 <P 3 故选B |