一袋中有6个芯片,编号为1到6,如果随机选择2个芯片,两个芯片编号的乘积大于20概率是多少
解
所有结果用15种,
{1,2}
{1,3}
{1,4}
{1,5}
{1,6}
{2,3}
{2,4}
{2,5}
{2,6}
{3,4}
{3,5}
{3,6}
{4,5}
{4,6}
{5,6}
积大于20的有两种
{4,6}
{5,6}
the probability that this product will be greater than 20 is Two fifteenths
如果是：what is the probability that this product will be no greater than 20?,选择【E】
意思是不大于20的概率,看看是否少一个：no