一袋中有6個(gè)芯片,編號為1到6,如果隨機(jī)選擇2個(gè)芯片,兩個(gè)芯片編號的乘積大于20概率是多少
解
所有結(jié)果用15種,
{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}
積大于20的有兩種
{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?,選擇【E】
意思是不大于20的概率,看看是否少一個(gè)：no