Question

掷两颗骰子，朝上点数的乘积大于 $10$ 的概率是

If two dice are tossed, the probability that the product of the numbers showing on the tops of the dice is greater than $10$ is

$\dfrac37$

$\dfrac{17}{36}$

$\dfrac12$

$\dfrac58$

$\dfrac{11}{12}$

答案：B

知识点：骰子（概率）系统列举

难度评级：1150

解答：

共有 $36$ 个等可能结果。按第一颗骰子的点数，计算乘积大于 $10$ 的有序数对：若为 $2$ ，有 $1$ 个结果满足，即 $2 \times 6$ ；若为 $3$ ，有 $3$ 个；若为 $4$ ，有 $4$ 个；若为 $5$ ，有 $4$ 个；若为 $6$ ，有 $5$ 个。

有利结果总数为 $1 + 3 + 4 + 4 + 5 = 17$ ，所以概率是 $\dfrac{17}{36}$ 。

所以正确答案是 B。

There are $36$ equally likely outcomes. Counting the ordered pairs whose product exceeds $10$ : with a first die of $2$ there is $1$ (namely $2 \times 6$ ); of $3$ , there are $3$ ; of $4$ , there are $4$ ; of $5$ , there are $4$ ; of $6$ , there are $5.$

That is $1 + 3 + 4 + 4 + 5 = 17$ favorable outcomes, so the probability is $\dfrac{17}{36}.$

Thus, the correct answer is B .

1992 AMC 8 第 23 题

答案：B

难度评级：1150

解答：

其他年份的第 23 题